The seasonal flu shot is a yearly vaccine administered to protect against the flu, or influenza. In the United States, flu shots are recommended for everyone ages 6 months and older, according to the Centers for Disease Control and Prevention (CDC). 

The flu can be a very serious illness, especially in young children, adults ages 65 and over, those with underlying health conditions and pregnant women. The flu shot is the best way to protect yourself and your family from the flu, according to the CDC.

Strains of the flu virus are constantly changing, so a new flu vaccine is made each year. Scientists make the vaccine before the flu season starts by predicting which flu strains are likely to be the most common during the upcoming season.

"Since the flu virus frequently drifts in its genetic composition, you have to reformulate the vaccine, and this is one of the reasons that people have to [get a flu shot] on an annual basis," Dr. William Schaffner, a preventive medicine and infectious disease expert at the Vanderbilt University School of Medicine in Tennessee told Live Science.

When should you get a flu shot?

Exactly when the flu season starts and ends is unpredictable, so health officials recommend that people get their flu shot in early fall, ideally by the end of October, according to the CDC. Flu activity typically peaks in February.

"We'd like to get as many people protected against influenza before influenza becomes active in communities across the country," Schaffner said.

Most flu vaccines are given before Thanksgiving, Schaffner said, but people can still get their shot throughout the winter months. Each season's flu shot expires in June of that year, but Schaffner said he would consider it "too late" to get a flu vaccine after March, unless a person is traveling to the Southern Hemisphere (where the flu season will then be starting).

After vaccination, it takes a person about two weeks to build up immunity against the flu.

People can visit the CDC's Vaccines.gov website to find flu shot locations.

Who should NOT get a flu vaccine?

Children younger than 6 months cannot get a flu shot. Those who have had a severe allergic reaction to a flu vaccine in the past should not get that type of flu shot again, and they should speak with their health care provider about whether they can receive another type of flu shot, according to the CDC. 

Similarly, people who have had a life-threatening reaction to flu-vaccine ingredients besides egg proteins shouldn't get flu vaccines with those ingredients, and they should speak with their health care provider about whether there is a flu vaccine that's right for them, the CDC says. These other ingredients might include gelatin or antibiotics, which are added to some flu shots to prevent bacterial contamination during manufacturing. (Not all flu shots contain antibiotics.)

People with egg allergies can still receive any type of flu shot that's recommended for their age group, even if the flu shot is made with egg-based technology (and thus contains a small amount of egg protein), according to the CDC. Studies have found that people with egg allergies are very unlikely to experience a severe reaction to flu vaccines. People who've had a severe allergic reaction to eggs should get their flu shot under the supervision of a health care provider who can treat severe allergic reactions, the CDC says. In addition, several types of flu shots are egg-free, including recombinant flu vaccines and cell-based flu vaccines. 

People with a history of Guillain-Barré syndrome (GBS), a rare, acute autoimmune disease that can cause paralysis, should talk with their doctor about whether they can get a flu vaccine. Some people with this condition cannot get a flu shot, according to the CDC. The cause of GBS is not known, but it is often linked with infections with viruses or bacteria; and in very rare cases, the condition has been linked with flu vaccination.

If you're not feeling well, you should talk to your doctor before getting a flu shot while you have symptoms. You should not get the flu vaccine if you have a high fever; you should wait until the fever is gone, according to Schaffner. However, if you have a minor illness, like a mild cold or a headache, you may still be able to get a flu shot.

Flu shot side effects

According to the CDC, mild side effects from the flu shot include soreness, redness or swelling at the injection site; low-grade fever; and aches. Only about 1% to 2% of people who get a flu shot will have fever as a side effect, Schaffner said. These mild effects should go away within a few days.

Rare but serious side effects can occur, including allergic reactions. Symptoms of serious side effects include difficulty breathing, swelling around the eyes or lips, hives, racing heart, dizziness and high fever, according to the CDC. If you experience serious side effects, you should seek medical care immediately. In addition, it's important to ask your health care provider to file a Vaccine Adverse Event Reporting System report either online or by calling VAERS at 1-800-822-7967, the CDC says.

The flu nasal spray vaccine, which is approved for healthy, non-pregnant people ages 2 to 49, can cause a slightly different set of side effects compared with other types of flu shots. For children, side effects of the flu nasal spray can include runny nose, wheezing, headache, vomiting, muscle aches and fever. For adults, side effects from the nasal spray might include runny nose, headache, sore throat and cough. These side effects last a short time compared with the actual flu illness, the CDC says.

How effective is the flu vaccine?

The effectiveness of the seasonal flu vaccine depends upon several factors, including how well the flu strains in the vaccine match the strains in circulation. Some studies show that when the strains in the vaccine are a good match with the ones that are circulating, vaccinated individuals are 40% to 60% less likely to visit the doctor for flu illness than people who aren't vaccinated, according to the CDC.

Flu vaccine effectiveness can also vary depending on the age and health status of the person being vaccinated. For example, older adults may have a weaker immune response to the H3N2 component of the flu vaccine (the component that protects against the H3N2 flu strain), according to the CDC.

Benefits of the flu vaccine

But even though flu vaccines don't offer 100% protection against illness, there are numerous benefits to vaccination. For example, several studies have found that individuals who do get sick with the flu develop less-severe symptoms if they are vaccinated. A 2021 study published in the journal Vaccine that reviewed data from multiple flu seasons found that, among adults who were hospitalized with the flu, those who were vaccinated were 26% less likely to be admitted to the intensive care unit (ICU), and 31% less likely to die from flu, compared with those who were unvaccinated, according to the CDC. And according to a 2018 study, among adults admitted to the ICU for flu between 2012 and 2015, vaccinated patients spent four fewer days in the hospital, on average, than those who were not vaccinated.

Related: Why is the flu shot less effective than other vaccines?

What kinds of flu shots are there?

Flu shots known as "quadrivalent vaccines" protect against four strains of flu virus. These include two influenza A strains H1N1 and H3N2 — and two influenza B strains — the lineages B/Yamagata and B/Victoria. All flu shots for the 2022-2023 flu season are quadrivalent, according to the CDC.

In addition to the standard-dose flu vaccine given through a needle, flu shots are available in several other forms. These include a high-dose version for people ages 65 and older; an "adjuvanted" version that contains an ingredient that helps boost the immune response to the vaccine for ages 65 and older; a "cell-based" version that's grown in animal cells rather than in hens' eggs and is approved for people ages 6 months and older; a "recombinant" vaccine that does not use the full influenza virus or chicken eggs in the production process and is approved for people ages 18 and older; and a nasal spray, which is approved for healthy people ages 2 to 49 but not for pregnant women or those with weakened immune systems.

There is also a needle-free flu shot, delivered by a so-called jet injector, which uses a high-pressure stream of fluid to inject the vaccine, the CDC says. It is approved for adults ages 18 to 64. 

Starting in the 2022-2023 flu season, the CDC recommends that people ages 65 and older preferably get vaccinated with one of the three following flu vaccines: the high-dose flu vaccine, called Fluzone High-Dose Quadrivalent vaccine; the adjuvanted flu vaccine, called Fluad Quadrivalent adjuvanted flu vaccine; or the recombinant flu vaccine, called the Flublok Quadrivalent recombinant flu vaccine. This recommendation was made because recent studies suggest that these vaccines are potentially more effective for older adults compared with other versions of the flu shot, according to the CDC. Among these three vaccines, the CDC does not recommend one over the other, as they were all linked with increased protection for older adults. But if the recommended shots aren't available, older adults shouldn't wait to get vaccinated and should receive a standard-dose version of the shot instead.

What's in this year's flu vaccines?

The composition of the 2022-2023 flu shot is different from last season's flu shot. Specifically, one influenza A component of the flu shot (H3N2) and one influenza B component of the shot (Victoria lineage) were updated for the 2022-2023 season. 

According to the CDC, the 2022-2023 quadrivalent egg-based flu shot contains the following strains of the flu virus:

• A/Victoria/2570/2019 (H1N1) pdm09-like virus
• A/Darwin/9/2021 (H3N2)-like virus (updated from last year's shot)
• B/Austria/1359417/2021-like virus (B/Victoria lineage) (updated from last year's shot)
• B/Phuket/3073/2013-like virus (B/Yamagata lineage)

Then, there are the two types of flu vaccines that don't involve eggs: cell-based and recombinant-based flu vaccines. In cell-based flu vaccines, the inactivated flu virus is grown in cultured cells from mammals rather than in hens' eggs. Recombinant flu vaccines are created synthetically: To make this type of vaccine, scientists combine a lab-made antigen specific to the flu virus with a baculovirus (this type infects only invertebrates, not humans).

For the 2022-2023 season, these two types of flu vaccines contain the same components as the egg-based vaccine except the H1N1 component, which in the cell- or recombinant-based flu vaccines will be A/Wisconsin/588/2019 (H1N1) pdm09-like virus, according to the CDC.

What's flu activity like this season?

As of mid-September, flu activity in most of the U.S. was low or minimal. But activity is already increasing in Texas, New Mexico and Georgia, which are currently reporting moderate levels of flu activity, and the District of Columbia, which is reporting high flu activity, according to the CDC.

Even if flu activity is currently low in your community, you shouldn't wait to get your flu shot. Flu activity could begin to increase at any time, and it takes people about two weeks after receiving their shot to develop antibodies against flu viruses, the CDC says.

Some health experts are warning that flu season could be bad this year, based on what was seen in the Southern Hemisphere, which experiences its flu season during the summer months.

"I do think it's going to be a worse year [for flu] than we've seen in the last few years," Dr. Bessey Geevarghese, a pediatric infectious disease physician at Northwestern Medicine Central DuPage Hospital in Illinois, told The New York Times. The end of most COVID-19 restrictions has opened the door for the return of flu. What's more, people are likely more susceptible to flu this year because they've had less exposure to the virus over the past two years during the pandemic, Geevarghese told the Times.

Flu shot and COVID-19: Your questions answered

How do I know if I have the flu or COVID-19?

Symptoms of COVID-19 and the flu can be similar, but your doctor can order a test to determine if you have COVID-19 or the flu. There are even tests that check for both flu viruses and SARS-CoV-2, the virus that causes COVID-19, at the same time. 

Should I get a flu shot during the COVID-19 pandemic?

Yes, getting a flu shot every year is the best way to protect yourself and others from the flu. You can take precautions to protect yourself from COVID-19 while getting a flu shot, such as getting vaccinated against the coronavirus and wearing a mask.

Will a flu vaccine protect against COVID-19?

No, flu shots do not protect against SARS-CoV-2. (Separate vaccines against SARS-CoV-2 have been approved or authorized for emergency use in the U.S.) But flu shots do protect against strains of seasonal flu viruses and can reduce your risk of getting sick from the flu, as well as the risk of hospitalization and death from flu, according to the CDC.

Can I get a COVID-19 shot and flu shot at the same time?

Yes, people can get a flu vaccine and a COVID-19 vaccine — including the new COVID-19 bivalent booster shot — at the same time, according to the CDC. People tend to experience a similar set of side effects, and receive the same protection from diseases, whether vaccines are given alone or with other vaccines, according to the CDC. However, people may be slightly more likely to experience systemic side effects, such as fatigue and muscle aches, if they receive both shots at the same time. A study published July 15, 2022, in the journal JAMA found that people who got a flu shot and a COVID-19 booster shot at the same time were 8% to 11% more likely to have systemic side effects, compared with people who received just a COVID-19 booster shot. But these side effects tended to be mild and resolve quickly, according to the CDC.

If you haven't been vaccinated against COVID-19, you should get vaccinated as soon as possible to protect yourself from the disease and stay up to date with COVID-19 booster shots, and you should aim to get a flu shot by the end of October.

Myth #1: You get the flu from the flu shot.

"It's a myth that you can get flu from the flu vaccine," Schaffner said.

The viruses in the flu shot are killed, so people cannot get the flu from a flu vaccine. However, because it takes about two weeks for people to build up immunity after they get the flu vaccine, some people may catch the flu shortly after they've been vaccinated if they are exposed to the flu during this time period. Some people may also mistakenly attribute symptoms of a cold to the vaccine, Schaffner said.

The nasal spray vaccine contains a "live attenuated" flu virus, but the virus is weakened so that it cannot cause the flu. The viruses in the nasal spray can't replicate in the warm temperatures of the lungs and other parts in the body. However, because temperatures in the nose are colder, the virus causes a small infection in the nose. This infection does not cause symptoms in most people, but in some people, it causes symptoms such as runny nose and sore throat, Schaffner said. These symptoms are typically short-lived, the CDC says.

This local infection will prompt the body to make antibodies against the flu virus, Schaffner said. "That provides better protection against the real flu, which is, of course, a virus that can make you seriously ill," Schaffner said.

Myth #2: The flu vaccine isn't safe for pregnant women.

Studies show flu vaccines are safe for women in any stage of pregnancy, the CDC says. There are several reasons why it's important for pregnant women to get a flu shot, Schaffner said.

"Pregnant women, when they get influenza, have a tendency to get a more severe disease" and are at increased risk for complications and hospitalization from the disease, Schaffner said.

In addition, flu vaccination in pregnancy helps to protect the baby against flu during the first six months of life, when the baby is too young to receive a flu shot, Schaffner said. The mother "passes that protection on to her newborn baby," Schaffner said.

Related: Am I pregnant? 12 early signs of pregnancy

Myth #3: Antibiotics can fight the flu if you get it.

Antibiotics only kill bacteria, but the flu is caused by a virus. Therefore, antibiotics do not help people recover from the flu.

There are antiviral drugs that can fight flu infections, but they've only been shown to work when they're given within 48 hours of the start of symptoms. "Most people, by the time they go to the doctor, they're past the 48-hour mark," said Dr. Dennis Cunningham, system medical director of infection prevention at Henry Ford Health System in Detroit.

For patients hospitalized with severe flu, the drugs may help, he said. But they aren't a cure, and for most people who aren't hospitalized, these drugs may only cut down on the duration of the flu by a day or two.

Myth #4: You don't need to get the flu vaccine every year.

There are two reasons doctors recommend that people get the flu vaccine every year, Cunningham told Live Science.

For one, the strains of the flu virus that are circulating change from year to year. "It's like the common cold — there's more than one type of virus that causes the flu," and, in fact, there are hundreds of influenza viruses, he said. Each year, health officials identify the virus strains that are the most likely to cause illness during the upcoming flu season, according to the CDC.

Second, the immunity you develop after getting the shot wanes by the following year. "If you get your shot in August, you'll be safe through March, but those antibodies won't be for the next flu season," Cunningham said.

Myth #5: It contains thimerosal, which may be harmful.

Thimerosal, a preservative that contains mercury, has never been shown to be harmful, Cunningham said. The type of mercury linked with nervous system damage is called methyl mercury, he said. Concerns over levels of methyl mercury have led to recommendations that pregnant women avoid eating large amounts of certain types of fish, such as swordfish.

In contrast, thimerosal is an ethyl mercury compound that has antimicrobial properties. Still, because the preservative raised controversy, especially over a now-disproven link to autism, it was taken out of almost all U.S. vaccines starting in 2001, Cunningham said.

The injectable form of the flu vaccine is available to health care providers as large, multidose bottles and small vials carrying individual doses. A tiny amount of thimerosal is added to the multidose bottles to ensure that no bacteria will grow in the vaccine, Cunningham said. The individual-dose bottles contain no thimerosal. 

The nasal spray form of the flu vaccine also contains no thimerosal, he noted.

Myth #6: The flu isn't serious.

"The flu is certainly a very serious disease," Cunningham said.

Every year, between 15 million and 60 million cases of the flu are reported in the U.S., Cunningham said. More than 200,000 people with the flu are admitted to hospitals yearly, and between 3,000 and 50,000 people in the U.S. die of the flu annually. During the 2019-2020 flu season (the last flu season with data available before the COVID-19 pandemic), the CDC estimated that 38 million Americans were infected with the flu and 22,000 people died from it.

One reason people may not perceive the flu as being serious is that cases of the "stomach flu" are mistaken for influenza virus infections. "True influenza is an infection of the lungs and respiratory tract," Cunningham said. Infected people may develop a high fever, body aches and nasal congestion, he said.

People with the stomach flu — which is commonly caused by a type of virus called a norovirus — have diarrhea, cramping and other gastrointestinal symptoms. Influenza does not typically cause such symptoms.

This article is for informational purposes only and is not meant to offer medical advice.

Editor's note: This article was last updated on Sept. 22, 2022. Live Science staff writer Nicoletta Lanese and contributor Rachael Rettner contributed to this report.

Originally published on Live Science.

More than 3.8 million babies were born each year in the United States on average from 2010 to 2020, according to the National Center for Health Statistics. But in which month are the most babies born, and why?

In the United States, the month with the largest number of births is typically August, with July a close second, Brady Hamilton, a demographer with the National Center for Health Statistics, told Live Science.

For example, August saw the greatest number of births in eight of the years from 2010 to 2020, Hamilton noted. July nabbed first place in three of those years — 2014, 2015 and 2020, he said.

Related: What is the birthday paradox?

In 2021, August was again the leading month, seeing 329,978 births, compared with an average of 350,067 births from 2010 to 2020. The smallest number of births in 2021 occurred in February, which saw 266,308 births, according to the National Center for Health Statistics.

Since the full course of a pregnancy is normally about 40 weeks, or a little more than nine months, these data suggest most children in the United States are conceived in November or December, Hamilton noted. "It's a fascinating question why that is," Hamilton said.

Reproduction appears to be seasonal in many living organisms — including plants, insects, reptiles, birds and  mammals — likely to help maximize their chances of reproduction over the course of their lifetimes, Micaela Martinez, an assistant professor of environmental health sciences at Columbia University in New York, and Kevin Bakker, previously an assistant research scientist at the University of Michigan and now a principal scientist at Merck, wrote in an essay for The Conversation.

In a 2014 study in the journal Proceedings of the Royal Society B: Biological Sciences, Martinez, Bakker and their colleagues noted that there was a clear pattern of births across latitudes in the United States: Northern states have a birth peak in June and July, whereas Southern states experience a birth peak later, in October and November.

The 2014 study found a similar pattern across the Northern Hemisphere, with peaks occurring later in the year the closer the location was to the equator. For instance, Finland saw the most births in late April, whereas Jamaica's births peaked in November.

So what could explain this correlation?

A 1990 study in the Journal of Biological Rhythms suggested the seasonality of human births may be linked with local temperature and day length. The extent to which temperature and day length may or may not change seasonally over the year depends in part on latitude, Martinez and Bakker noted. These environmental changes may influence the frequency of sex or how fertile men or women are, they noted. However, in their 2014 study, they note many other factors may play a role as well, such as income, culture, holidays and rainfall, making it challenging discussing whether and in what way temperature or day length might affect human births.

Understanding when most human births happen is more than just a matter of trivia, Hamilton said.

"If you're the birthing ward of a hospital, or a company that makes baby formula, or a diaper manufacturer, it's good to know what you might be facing over time," Hamilton said. "Further down the line, school systems may want to anticipate how many children may be coming in at a certain point in time, and health care systems would want to know what to expect in terms of inoculations."

Originally published on Live Science on July 27, 2010 and rewritten on Aug. 19, 2022.

While there's no fountain of youth, a Tibetian Buddhist monk may have tapped into the next best thing, according to an analysis showing that his 41-year-old brain actually resembles that of a 33-year-old. 

The monk, Yongey Mingyur Rinpoche (YMR), a renowned meditation practitioner and teacher, began meditating at age 9. The "extraordinary number of hours" that YMR spent meditating may explain why, in part, his brain looks eight years younger than his calendar age, researchers of a new longitudinal study said. (A longitudinal study looks at the same metric over time.)

The findings add to a growing pile of evidence "that meditative practice may be associated with slowed biological aging," the researchers wrote in the case study, published online Feb. 26 in the journal Neurocase.

Related: Mind games: 7 reasons you should meditate

In the study, done at the Center for Healthy Minds at the University of Wisconsin-Madison, researchers used structural MRI (magnetic resonance imaging) to scan the brain of YMR four times over the course of 14 years, starting when he was 27 years old. 

During this time, 105 adults from the Madison, Wisconsin, area who were about the same age as YMR also had their brains scanned. These people became the control group, so researchers would know what normal brain aging looked like.

After the MRI scans were collected, the researchers used a machine learning tool called the Brain Age Gap Estimation (BrainAGE) framework, which estimates the age of a person's brain by looking at its gray matter. 

Taking an inventory of gray matter structure is a good way to tell brain age, said the study's senior researcher, Richard Davidson, professor of psychology and psychiatry at the University of Wisconsin-Madison and founder and director of the Center for Healthy Minds. "Gray matter is the neural machinery of the brain," Davidson told Live Science. "When the brain atrophies, there is a decline in gray matter."

BrainAGE's analysis revealed that YMR's brain had delayed aging in comparison with the controls, who fell onto the "typical aging band" when graphed, the researchers found. 

"The big finding is that the brain of this Tibetan monk, who has spent more than 60,000 hours of his life in formal meditation, ages more slowly than the brains of controls," Davidson said. 

BrainAGE also showed that specific regions of YMR's brain didn't differ from controls, "suggesting that the brain-aging differences may arise from coordinated changes spread throughout the gray matter," the researchers wrote in the study. 

Early maturity 

In addition, the BrainAGE analysis found that YMR's brain had matured early. It's not clear what this means, Davidson said, although the researcher did offer one idea.

"There are areas of the brain that come online in the mid- to late 20s, for example, regulatory regions of the brain that play an important role in self-regulation, in regulating our attention," Davidson said. "It may be that these areas are maturing earlier in the meditators, and that would make sense, because we believe that meditation can strengthen these areas and these kinds of functions [in the brain]."

Other research by the Center for Healthy Minds shows that certain kinds of meditation can strengthen these regulatory skills, Davidson noted. 

However, there is still much to learn. This case study examines just one meditator, and an accomplished one at that. It remains a mystery how much meditation is needed before these gray matter changes take place, Davidson said. 

Furthermore, YMR's life is unique. At age 12, he was formally enthroned as the seventh incarnation of Yongey Mingyur Rinpoche. As a teenager, he became a retreat master, responsible for guiding senior monks and nuns through the intricacies of Buddhist meditation practice over a three-year period, the researchers wrote in the study. YMR continued to live an accomplished life, and he participates in studies, including this one, to help scientists learn more about meditation and the brain.

In short, it's unclear if his "young" brain is the result of meditation, other factors in his life or all of the above. For instance, it's possible that people born in the high mountains of Tibet have brains that age more slowly, Davidson said. Or maybe YMR has a healthy diet and lives in areas with less pollution. A control group of people with similar backgrounds to YMR might help researchers better suss out answers to these questions. 

Davidson noted, however, that it's unknown whether having a young brain means that a person will live longer. 

Even so, the study suggests that meditation can be healthy for those who practice it, said Dr. Kiran Rajneesh, a neurologist at The Ohio State University Wexner Medical Center, who was not involved with the research.

"It kind of makes sense biologically, because stress is a thing that causes aging," Rajneesh told Live Science, "Not just psychological stress, which is definitely a part of it, but also stress happening at the cellular level."

Rajneesh added "it's definitely something each of us could take home. Perhaps doing those few minutes of meditation and slowing down our lives, even for some amount of time, is likely to help."

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Originally published on Live Science.

Eight teenagers in Wisconsin have been hospitalized with serious lung damage after vaping, according to health officials.

All of the teenagers were hospitalized during the month of July, according to Children's Hospital of Wisconsin, the facility where the teens were treated. These patients experienced a number of respiratory symptoms — including shortness of breath, chest pain, cough and fatigue — in the days and weeks leading up to their hospitalization. Some of the teens needed medical assistance to breathe. The teens also experienced nausea, diarrhea and weight loss.

All of the patients reported vaping in the weeks and months before their hospitalization, according to Children's Hospital of Wisconsin. Doctors haven't identified the exact cause of the teens' illnesses.

"It was alarming to have, over a short period of time, eight previously healthy teens come in very sick, unable to breathe, with weight loss, looking as if they had some sort of chronic lung disease when they didn't," Dr. Louella Amos, a pediatric pulmonologist at Children’s Hospital of Wisconsin, told the Milwaukee Journal Sentinel.

Some of the teens reported buying vaping products, including nicotine and THC, on the black market, the Journal Sentinel reported.

In general, the health effects of vaping are not fully understood, the hospital said.

"The popularity of vaping is obviously skyrocketing among our kids and its dangers are still relatively unknown," Dr. Michael Gutzeit, chief medical officer of Children's Hospital of Wisconsin, said in a statement. "We don't have a lot of information about the long-term effects or even the short-term effects."

The Wisconsin Department of Health Services is investigating the illnesses and recently sent out an alert to doctors asking them to be on the lookout for more cases. Officials are interviewing patients about the types of vaping products they used.

Most of the sick teens have responded to steriod treatment and have been released from the hospital, but one patient is still hospitalized, according to CBS News.

In addition to the eight confirmed cases, six more possible cases of teens with lung damage tied to vaping are being investigated, the Journal Sentinel reported.

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Originally published on Live Science.

A toddler died from an E. coli infection, and three other children fell ill with the same disease, after visiting the San Diego County Fair last month, according to health officials.

On Friday (June 28), the San Diego County Health and Human Services Agency announced that four children ages 2 to 13 had become infected with E. coli after attending the fair from June 8 to June 15.

In three of the four cases, the children were not ill enough to require hospitalization. But one child, a 2-year-old boy, was hospitalized and died from complications of the disease on June 24, the agency said in a statement.

All of the children were infected with Shiga-toxin-producing E. Coli (STEC).

Although most people recover from this illness, about 5% to 10% of those infected will develop a life-threatening kidney infection, the statement said.

The Shiga toxin produced by the bacteria destroys red blood cells, and those damaged blood cells can block the kidneys' filtering system, leading to a condition known as hemolytic uremic syndrome (HUS), according to the National Institute of Diabetes and Digestive and Kidney Diseases.

HUS can lead to kidney failure, which itself can be fatal. However, people don't usually die from kidney failure anymore, because it can be treated with dialysis, Dr. Amesh Adalja, a senior scholar at the Johns Hopkins University Center for Health Security, told Live Science in an interview last year.

Instead, most deaths associated with HUS result from other complications, such as bleeding (due to the toxin interfering with blood clotting), stroke or brain swelling, Adalja said. In addition, since an E. coli infection causes diarrhea, it can also cause a tear (perforation) in the colon, which allows fecal matter to leak into the body, and this can also be deadly, he said.

The source of the children's infection is still under investigation, but all of the sick children visited animal areas at the fair, such as the petting zoo, the statement said. Fair officials have now closed public access to all animal areas.

To prevent a STEC infection, health officials recommend washing hands often, including after contact with animals or their environments (such as farms, petting zoos, etc.) and before eating and drinking, the statement said.

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Originally published on Live Science.

Mothers who eat a high-fiber diet in pregnancy may lower the risk of celiac disease in their children, a new study suggests.

The study researchers analyzed information from more than 88,000 Norwegian children and their mothers, who gave birth between 1999 and 2009. The mothers were asked about their fiber and gluten intake in their 22nd week of pregnancy, and the children were followed for about 11 years for a diagnosis of celiac disease.

The researchers found that mothers with the highest fiber intake — more than 45 grams (1.6 ounces) per day — were 34% less likely to have children diagnosed with celiac disease, compared with mothers with the lowest fiber intake, of less than 19 grams (0.7 ounces) per day. [Are You Pregnant? 12 Early Signs of Pregnancy]

The study is one of the first to examine the link between fiber intake during pregnancy and children's risk of celiac disease.

The researchers cautioned that their findings are preliminary. "We cannot yet recommend any specific dietary measures during pregnancy to prevent celiac disease, and this needs to be further studied," study lead author Dr. Ketil Størdal, a research professor at the Norwegian Institute of Public Health and a pediatric gastroenterologist at Østfold Hospital Trust in Norway, said in a statement.

However, the study didn't find a link between the mother's gluten intake and her child's risk of celiac disease. "Our findings do not support gluten restriction for pregnant women," Størdal said.

The study will be presented Friday (June 7) at the annual meeting of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). It has not yet been published in a peer-reviewed journal.

Celiac disease is a condition in which people's immune systems react to gluten — a protein found in wheat, rye and barley — damaging the lining of the small intestine. The condition affects about 1 out of every 100 people in the United States and most European countries. Currently, the only way to manage celiac disease is for patients to avoid foods containing gluten for the rest of their lives.

In the new study, celiac disease was diagnosed in 982 children, or 1.1% of all children in the study.

For every 10-gram (0.4 ounces) increase in a mother's daily fiber intake, there was an 8% reduction in her child's risk of celiac disease. Fiber intake from fruits and vegetables, rather than cereals, was tied to the lowest risk of celiac disease.

It's known that fiber affects the bacteria in people's guts (the gut "microbiome"). The researchers hypothesized that a mother's fiber intake may affect her child's gut flora, which in turn could affect the risk of celiac disease. (Indeed, some studies have found that people with celiac disease have an altered gut microbiome compared to those without the condition.)

However, much more research is needed to prove the researchers' hypothesis, and the authors plan to conduct future studies on how a mother's fiber intake affects her child's gut flora, Størdal said.

It's recommended that pregnant women eat about 25 grams (0.9 ounces) of fiber per day, the same recommendation as for the general population, according to the The American College of Obstetricians and Gynecologists.

• 11 Big Fat Pregnancy Myths
• 18 Ways Pregnancy Changes Your Body Forever
• 5 Key Nutrients Women Need As They Age

Originally published on Live Science.

When babies pass through the mother's birth canal, the tight fit temporarily squashes their wee heads, elongating their flexible skulls and changing the shape of their brains. Now, scientists have created 3D images that demonstrate the extent of that amazing conehead-like distortion.

Babies' heads can change shape under pressure because the bones in their skulls haven't fused together yet, according to the Mayo Clinic. Soft regions at the top of the head accommodate being squeezed through the birth canal and allow room for the brain to grow during infancy.

However, the precise mechanics of how a baby's skull and brain change shape during labor are not well understood. To learn more about that process, scientists conducted magnetic resonance imaging (MRI) scans of seven pregnant women: when the subjects were between weeks 36 and 39 of their pregnancies, and then when they were undergoing labor, after their cervixes were fully dilated. [7 Baby Myths Debunked]

Their images revealed significant skull squeezing — known as fetal head molding — in all the infants, and suggested that the pressures exerted on infant heads and brains during birth are stronger than once thought, scientists reported in a new study.

In all seven fetuses, skull bones that did not overlap prior to labor were visibly overlapped once labor began, deforming the infants' heads and brains, the researchers wrote. In five babies, the skulls returned to their prelabor shapes soon after birth, and the deformation was not noticeable when the newborns were examined.

The MRI scans captured views of soft tissues that were not visible with ultrasound, providing important clues for understanding the deformation of fetal skulls and brains, and the movement of maternal soft tissues around them during birth, according to the study. 

The findings were published online today (May 15) in the journal PLOS One.

• 11 Big Fat Pregnancy Myths
• Wonder Woman: 10 Interesting Facts About the Female Body
• Trying to Conceive: 10 Tips for Women

Originally published on Live Science.

If babies had a universal trait, it would have to be their babbling. During the earliest months of their lives, babies' interactions with us basically boil down to strings of ba's, ga's and da's, punctuated by the occasional gurgle or wet raspberry.

But does this seemingly random string of sounds serve any purpose — other than to entertain besotted parents and fuel adorable social media clips? A growing body of research over the past few decades has revealed that, nonsensical though it may sound, a baby's babble actually lays the groundwork for the development of language in later life.

Amid the varied soundscape of coos, gurgles and other random noises that babies emit, babbling is recognized as a distinctive category of sound that kicks in around the 6- to 8-month mark of a baby's life. It can be defined as "the production of repetitive, speech-like syllables," said Catherine Laing, a linguistics researcher at Cardiff University in the United Kingdom, who focuses on early language development in infants. "Babble is the beginning of learning the sounds that can be used in speech," she summarized. [Why Do Babies Kick in the Womb?] 

Babble is also noticeable enough that anyone paying attention to a baby's vocalizations will notice when it begins, according to Marilyn Vihman, a professor of language and linguistic science at the University of York in the United Kingdom, who has written several books on language development: "It's a really sharp change which adults can recognize. You don't have to be a linguist to recognize it."

However, being able to detect the different phases through which babble unfolds may require a closer listen. Starting out, babies will produce a range of different consonants that they develop a habit of repeating very rhythmically. Soon after, they will typically limit their exploratory inventory to just one or two consonants that they start to repeat more frequently — as in, "babababa!" or "dadadada!" Laing told Live Science. "Having a couple of different consonants that you can produce at will seems to be a prerequisite for really beginning to do words," Vihman said. "It's kind of a predictor for being able to get word forms under control, so that you can make words that people will recognize."

At this stage, babies seem to perform these long syllabic strings as a kind of reflexive motor behavior, without recognizing its practical value. But soon, those strings graduate into shorter, more clipped expressions that start to resemble words. This is something that Vihman has explored in depth over the course of her research. It's thought that this shift is driven by the baby's growing awareness of the words that adults around them are speaking — and their desire to mimic them. "Adults are like gods in their universe, the people that provide comfort, warmth and social stimulation. So the big motivation for the baby is to be like the adults," Vihman told Live Science.

Intriguingly, research shows that deaf babies also start babbling like hearing ones; it's just slightly delayed. But that progress grinds to a halt at the stage where their babble would start to sound more word-like, because deaf babies can't hear the words of the adults they'd ordinarily be trying to mimic. In hearing babies, however, after a few more months of practicing these shorter syllables, they've "picked up on word forms that are similar to the babble they're able to produce," Vihman explained. This becomes the essential bridge that equips them to start repeating words they often hear — words that they might realize have an association with something, or an impact on their listeners. (Think: "uh-oh" and "bye-bye.") [Why Do Babies Barely Blink?]

At this point — usually between the 10- to 15-month mark — babies will dish up a melange of babble and fully formed words. By the time they have a repertoire of 20 to 30 words that they're speaking regularly, what they're doing is probably defined less as babble and more as speech, Vihman said.

And, if you have any lingering doubts about the profound influence of babble on shaping language, there are several fascinating studies that have demonstrated its importance. For example, premature babies who've had tracheostomies inserted into their lungs to help them breathe are unable to make babbling sounds like healthy babies. But research has shown that when these tracheostomies are removed, babies will start babbling — even if it's several months after it should have first begun. "They still go through a babble period before they start to produce words. They sort of pick back up," Laing said — highlighting the importance of babble in laying the groundwork for speech.

Similarly, hearing-impaired babies who receive a cochlear implant to help them hear again will soon start babbling, as if they're trying to catch up on everything they've missed. "Essentially, if you think about it, it's like rehearsing the different bits of the words that you're going to go on to produce. There's a sense of preparing yourself for word production," Laing said.

So what's the main takeaway from all of this? Since babble is a stepping-stone to language, it should be encouraged through plenty of communication with babies. And while some people might think that reciting Shakespeare is best for their offspring, you'd do just as well with a bit of baby talk. "Often parents worry, is it bad to use baby talk? There's no harm, as long as you're keeping pace with your baby's development, and that as they're understanding more, you're talking in a slightly more complex way," Vihman said.

Equally, for working parents who might feel concerned about how pressured schedules and weariness affect the quality of their time — and consequently, their chat — with their babies, Laing has an interesting perspective to share. Emerging research suggests that so long as someone is talking to them — whether another caregiver, a grandparent or a sibling — babies will benefit. "Babies can be quite resilient in terms of what they draw on as an influence," Laing said. "One-to-one interaction with parents is known to be important, but interactions with a wider range of speakers can support other kinds of learning."

• Why Do Babies Cry on Airplanes?
• Why Are Human Babies So Helpless?
• Why Baby Calms Down When Carried

Originally published on Live Science.

In August 2018, a baby boy was born in Tokyo weighing only 9.45 ounces (268 grams) — about the weight of a bag of potato chips.

The boy had stopped growing in his mother's womb, doctors at Keio University Hospital told Reuters, and had to be delivered by an emergency Caesarean section 24 weeks into the mother's pregnancy to avoid a stillbirth. But the baby was smaller and less developed than he should have been at 24 weeks, which is the youngest age most doctors consider "viable," meaning the child can survive outside the womb. He could not breath or eat on his own, and his entire body fit inside his parents' cupped hands.

But last week, on Feb. 20, after five months of treatment, that baby boy was finally discharged from Keio University Hospital and allowed to go home with his family. Though he now weighs a healthy 7 pounds (3.2 kilograms), he leaves the hospital with the distinction of being the world's smallest surviving male baby born in recorded history. [7 Baby Myths Debunked]

"There are only four babies this small [that survived] that we know of in the history of mankind," said Dr. Edward Bell, a professor of neonatal pediatrics at the University of Iowa's Carver College of Medicine. "It's exceedingly rare. And for boys, as far as I can tell, it's unique."

Bell is the founder and webmaster of the Tiniest Babies Registry, the University of Iowa's database of the world's smallest surviving babies born since 1936. The baby boy born in Tokyo last August ranks as the fourth-smallest child on Bell's registry, and is surpassed by three baby girls from Tokyo, Illinois and Germany, all born at 25 weeks and weighing 9.34, 9.17 and 8.88 ounces (265, 260 and 252 g), respectively.

Of the registry's 210 babies (all weighing under 14 ounces, or 400 grams, at birth), Bell told Live Science that roughly 75 percent are female. This is because males develop more slowly than females, both in the womb and in adolescence.

"In these cases of extremely early [birth] or extremely small children, girls are a little more developed than boys," Bell said, and that gives baby girls a slight survival advantage. "More boys are born, but more girls survive."

Often, Bell said, babies born so small stop developing in the womb because their mother's placenta is not properly delivering the oxygen and nutrients they need to grow. The boy from Tokyo had "unusually well developed" heart, lungs, brain and kidneys for a baby of his size, Bell said (the boy's physician had to provide these details to get the baby listed on Bell's registry), but chances are he will never catch up to the average height of other kids.

"Even if his parents are of average size, he is more likely to be one of the shorter kids in his class picture, for example," Bell said.

Babies born so small also face heightened risks of developing learning disabilities and health problems than children born at full term — however, Bell said, the outcomes truly seem to differ baby-to-baby.

"Some of the babies on the registry are severely handicapped," Bell said. "Some of them are having good lives, are college graduates and very talented individuals. You see the whole spectrum."

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• 7 Ways Pregnant Women Affect Babies
• 11 Facts Every Parent Should Know About Their Baby’s Brain

Originally published on Live Science.

It looks like someone drew a heart over a child's X-ray. But this cartoonish heart — which seemingly floats in the child's throat — is real, the result of a heart-shaped pendant that got stuck in the girl's esophagus.

The X-ray was taken when a 3-year-old girl was brought to the emergency room after she ingested the gold-colored pendant, according to a new report of the case, published today (Feb. 13) in The New England Journal of Medicine and appropriately titled "Heart of Gold."

The image confirmed there was a "heart-shaped foreign body" in the child's esophagus, the report said. [11 Weird Things People Have Swallowed]

Toddlers, of course, put all sorts of things in their mouths and sometimes swallow them. Potentially dangerous items, such as sharp objects and button batteries (which could tear or burn the esophagus), require immediate removal if swallowed, the report authors wrote. In addition, objects that have been stuck for more than 24 hours warrant removal.

But if a child swallows an item that doesn't appear to pose an immediate danger, the patient is observed for a limited period to "allow the foreign body to pass spontaneously," the report said. That was the case for this patient, who experienced no symptoms from the pendant.

In several more X-rays taken later, however, the pendant didn't appear to be budging from its location. So, doctors performed a nonsurgical procedure to remove the object. The child recovered well after the procedure and was sent home, the report said.

• 9 Weird Ways Kids Can Get Hurt
• 27 Oddest Medical Case Reports
• 12 Amazing Images in Medicine

Originally published on Live Science.

Whether you're the long-suffering parent or an unlucky passenger sitting in a neighboring row, a crying baby on an airplane is never fun. We've all been there. As the plane ascends or descends, baby feels the scary sensation of her or his ears popping, and a whimper that turns into a high-pitched shriek fills the cabin.

Of course, there are many reasons that a baby might cry on an airplane. Feelings of discomfort, exhaustion, hunger, loneliness, boredom, anger, pain and general unrest are all expressed by wails and tears, if not a total meltdown. However, there is general agreement that the pressure caused by flying at altitude is particularly difficult to bear for babies and toddlers. There is a fundamental anatomical difference between baby and adult ears, Dr. Simon Baer, a consultant ear, nose and throat surgeon in the United Kingdom, told Live Science. [Why Do Babies Barely Blink?]

"Certainly, one of the main reasons babies cry on planes is that they are not good at pressure equalization in the middle ear, as the infantile Eustachian tube does not generally function as well as [the one in] adults," Baer said.

The Eustachian tube is a canal connecting the middle ear to the nasopharynx — the upper throat and the back of the nasal cavity. Basically, this tube controls the pressure within the middle ear, making it equal to the air pressure outside the body. The Eustachian tube remains closed most of the time, opening only for activities such as yawning, swallowing and chewing, which allows air through the passage between the middle ear and nasopharynx. When atmospheric pressure changes rapidly, causing a sudden feeling of blockage in the ear (such as during airplane travel), most adults yawn or swallow on purpose to open the tube and equalize the pressure within the middle ear.

Baer added that the pressure is particularly problematic during the descent, as equalization is more difficult going from a low atmospheric pressure to a relatively higher one, which happens as the plane goes down for its landing.

"While the problem can occur on ascent, the way the tube works means that it is easier to adjust from a higher atmospheric pressure to a lower pressure, which is what happens when we ascend," he said. "Although modern aircraft are to a certain extent pressurized, there are still significant air pressure changes in the plane from the ground pressure to the pressure when flying at 30,000 feet [9,100 meters]."

But there are ways to help out baby's ears. Another good way to equilibrate the pressure differential in the middle ear is through the so-called Valsalva maneuver — that is, pinching the nose and blowing, according to a 2007 review in Paediatrics & Child Health, the official journal of the Canadian Paediatric Society.

Baer had even more advice.

"Three ways that can assist include making sure the baby is awake on ascent and descent, getting baby to suck a bottle at these times, and perhaps avoiding flying when the baby is suffering with an upper respiratory tract infection," Baer said.

Gordon Harrison, the chief audiologist at the U.K. optical and hearing retail chain Specsavers, told Live Science that a simple way to help ease the effects of pressure on the ear is to introduce as much air as possible to the ear via swallowing or yawning. However, he admitted that this is not always easy when dealing with a hysterical 1-year-old.

"It's much easier to mitigate the effects of ear pressure in adults than in babies," Harrison said. "However, while tricks like sucking on a hard-boiled sweet, chewing gum, yawning or drinking through a straw during takeoff and landing all help, these are obviously not things a baby can do."

Harrison also suggested giving the baby a bottle or pacifier to suck on during takeoff and landing, or breastfeeding at those times.

"Rest assured, though, that usually the pain is only temporary," he said. "It won't cause any lasting problems and most likely will ease within a few minutes as the Eustachian tubes open to let the air pressure equalize on both sides of the eardrums."

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• Why Are Human Babies So Helpless?

Originally published on Live Science.

Rates of a serious birth defect are on the rise in the United States, and a new report suggests the condition may be linked to opioid use.

The report, published Jan. 17 by researchers at the Centers for Disease Control and Prevention, looks at cases of gastroschisis, a birth defect in which a baby is born with his or her intestines outside the body, due to a hole in the abdominal wall. Surgery is required to place the intestines back in the body and to repair the hole, but even after this treatment, infants may have problems with digestion, eating and food absorption, according to the CDC. The cause of the condition is usually unknown, but mothers younger than 20 are thought to be at higher risk than older mothers.

The new report analyzed information on gastroschisis cases in 20 U.S. states and found that the rate of gastroschisis increased 10 percent from 2006 to 2010, to 2011 to 2015. Specifically, the report found that the rate of gastroschisis rose from 4.2 cases per 10,000 live births in 2006 to 2010, to 4.5 cases per 10,000 live births in 2011 to 2015. The largest increases were seen in babies born to mothers in their 20s and 30s. [7 Baby Myths Debunked]

The new report follows an earlier study that found that the rate of gastroschisis also increased between 1995 and 2012.

The reason for the increase is not known, but the new report hints at a link to the opioid epidemic. The researchers found that the prevalence of gastroschisis was 1.6 times higher in counties with high rates of prescription opioid use, compared with counties with low prescription opioid rates.

Still, the researchers noted that the study only found an association, and cannot prove that opioid use causes gastroschisis. The study examined opioid use and gastroschisis rates only at a population level, and did not have information on whether women who had babies with gastroschisis were exposed to opioids.

Dr. Saima Aftab, medical director of the Fetal Care Center at Nicklaus Children's Hospital in Miami, who was not involved in the study, said that this rise in occurrences of gastroschisis is concerning. And the fact that rates are rising not only in women under 20, who are thought to be at highest risk, but also in older age groups is "even more alarming," Aftab told Live Science. This suggests that "there's something changing" about the usual patterns of gastroschisis epidemiology.

Aftab noted that she and her colleagues have also noticed an increase in gastroschisis cases in their hospital's fetal program, even in the last six months.

Gastroschisis is a serious condition that can cause swelling, twisting and damage to the baby's intestines before birth, Aftab said. Even after surgery, it may take weeks for the bowels to start functioning, and babies may be in the neonatal intensive care unit (NICU) for months, she said.

The link to opioids seen in the new report is an interesting signal, said Aftab, though she also cautioned that the report cannot determine causality.

But "it does guide where we need to direct our research and how we can answer these questions," she said. For example, basic science studies in animals can look at whether opioids disrupt blood vessels or the bowel tissue when taken during pregnancy. And researchers can also look at whether there's a link among high-risk populations of women who use opioids in pregnancy.

"Having a better understanding of all possible effects of opioid use during pregnancy can help provide evidence-based information to health care providers and women about the potential risks to the developing fetus," the report concludes.

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Originally published on Live Science.

Homework written by a school kid in ancient Egypt has been preserved since the second century A.D. And the words on the slab may sound familiar to any kid whose parents worry about them falling in with a bad crowd.

An ancient lesson preserved on a wood-mounted wax slab about the size of a Kindle reads: "You should accept advice from a wise man only" and "You cannot trust all your friends."

Acquired by the British Library in 1892, the tablet hasn't been publicly displayed since the 1970s. The homework slab will be featured in an upcoming British Library exhibit called "Writing: Making Your Mark," which traces the evolution of writing over 5,000 years of human history, library representatives said in a statement. [In Photos: Ancient Egyptian School Discovered]

On the wax tablet is a two-part lesson in Greek that provides a snapshot of daily life for a pupil attending primary school in Egypt about 1,800 years ago, exhibit co-curator Peter Toth, also a curator of ancient and medieval manuscripts at the British Library, told Live Science in an email.

One part of the assignment was a writing exercise. The slab displays a teacher's written example in the first line, and the next two lines contain the same words copied "rather clumsily" in the student's hand, much as primary students today copy lines penned by their teachers, Toth said. The rest of the homework included a multiplication table and reading exercises.

Though the name and sex of the tablet's owner is unknown, the child was likely a boy from a wealthy family, as formal education in ancient Egypt was typically reserved for males of privilege, according to the Royal Ontario Museum.

Life lessons

Lines copied by this long-ago student were not just for practicing penmanship; they were also intended to impart moral lessons. "It's not only the hands and fingers but also the mind that is being instructed here," Toth said.

(As of yet, no ancient Egyptian homework has been discovered with the lines: "If your friends jumped into the Nile, would you do it too?" but it wouldn't be surprising.)

Homework slabs like this one were made by pouring melted, blackened wax into a rectangular depression at the center of a wooden tablet. Once the wax cooled, teachers and students could use a metal stylus to scratch letters that appeared as a lighter color against the dark background.

Wax typically breaks down in the presence of moisture, so the region's dry climate likely helped to protect the tablet, "preserving the clumsy handwriting of a primary school pupil from almost two millennia ago," Toth said.

Along with the homework slab, the exhibition brings together over 100 artifacts from the British Library collections to explore examples of writing from ancient civilizations to modern cultures. Objects include stone monuments bearing Egyptian hieroglyphs; a copy of the literary classic "Ulysses" annotated by author James Joyce; musical notes penned by Mozart; and contemporary tattooing instruments.

"Writing: Making Your Mark" will appear at the British Library from April 26 through Aug. 27, 2019.

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Original article on Live Science.

A Chinese researcher who ignited controversy in 2018 after claiming to have created the first genetically edited human infants was recently spotted in Shenzhen, China.

This is the first reported sighting of Jiankui He, an associate professor at the Southern University of Science and Technology of China, in weeks, The New York Times reported Dec. 28.

He was photographed while on the fourth-floor balcony of an apartment building — a university guesthouse — and was seen talking to a woman thought to be his wife. The apartment appeared to be monitored by "a dozen unidentified men," according to The Times. [10 Amazing Things Scientists Just Did with CRISPR]

He last appeared in public in November at the Second International Summit on Human Genome Editing in Hong Kong, where he spoke about his research and fielded outraged queries from the global scientific community. Since then, He's whereabouts have been uncertain, though rumors suggested he was under house arrest, The Times reported.

According to He, the babies — twin girls named Lulu and Nana — were genetically modified as embryos with a gene-editing tool called CRISPR-Cas9; He used CRISPR to snip out a gene and thereby render the infants resistant to HIV, he said in a video posted to YouTube on Nov. 25.

However, scientists around the world promptly denounced He's actions as highly irresponsible and potentially harmful to the babies. Genes perform more than one function and act in concert with many other genes, and it is not yet possible to say for sure that excising a single gene can be done safely and with no future consequences for human health, Live Science previously reported.

In fact, the gene that He deleted in the embryos — CCR5 — is known to assist in white blood cell function, Mazhar Adli, a geneticist at the University of Virginia School of Medicine, told Live Science. He may also have failed to adequately inform the babies' parents about potential risks prior to obtaining their consent to the gene editing.

Following the release of the video, He's university quickly denounced his research, issuing a statement the next day stating that it was "deeply shocked" at what He had done and claiming that He had been on unpaid leave from the university since February.

In the weeks after the Hong Kong conference and the launch of an investigation by the Chinese government, He's location was uncertain and university representatives denied that he was being held under house arrest on university grounds, Newsweek reported.

However, He's current location is a university hotel that houses visiting scholars, according to The Times. Four guards were stationed outside the door of He's apartment, but their affiliation is unknown. Neither Shenzhen's police department nor the university responded to The Times' requests for comments, The Times reported.

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Original article on Live Science.

Parents who fear their kids are spending too much time in front of screens now have more reason for concern.

New research funded by the National Institutes of Health found brain changes among kids using screens more than seven hours a day and lower cognitive skills among those using screens more than two hours a day.

When studies find links between screen time and negative outcomes, some have argued that this is just the latest moral panic over technology.

After all, didn't the parents of baby boomers and Gen Xers worry that their kids were watching too much TV or talking on the phone too much? Those kids turned out OK, right?

So how are portable electronic devices, the chosen technology of today's kids and teens — a generation I call "Gen" — any different?

New research I've conducted on the relationship between portable device use and sleep provides some answers.

Everywhere, all the time

It almost goes without saying that today's portable devices — including smartphones and tablets — are fundamentally different than the living room television sets and rotary phones of the past.

Since researchers have been tracking TV watching habits, the average U.S. teen has never spent more than two-and-a-half hours a day watching TV. Yet as of 2016, the average teen spent about six hours a day immersed in digital media — more than twice as much time.

This large amount of time spent using digital media is enough to crowd out time once spent on other activities, such as interacting with friends face to face, reading or going out.

And unlike the telephone, digital media apps are designed to hook you. As former Silicon Valley executive Tristan Harris said of smartphone apps, "Your telephone in the 1970s didn't have a thousand engineers … updating the way your telephone worked every day to be more and more persuasive."

Second, unlike TV or landline phones, portable devices can be carried everywhere: to school, where teachers say they are a near-constant distraction, and into social situations, where a conversation can instantly be upended by reaching for a buzzing phone. (There's even a word for this: phubbing, a portmanteau of "phone" and "snubbing.")

Sure enough, people have reported enjoying a restaurant dinner with friends less when their phones were available, compared to when they weren't.

The sleep factor

Across many studies, kids and teens who spend more time with screens — including both TV and portable devices — also sleep less.

That could be because they spend so much time engaged with their devices that it's coming at the expense of sleep. But there's also a physiological reason: The blue light emitted by electronic screens tricks our brains into thinking it's still daytime, and then we don't produce enough of the sleep hormone melatonin to fall asleep quickly and get high-quality sleep.

Once again, some might argue that TV is just as bad: After all, it also takes up time and emits blue light.

But in a new paper, my co-authors and I decided to parse the two. We studied links between sleep and TV watching as well as links between sleep and portable device use. Then we compared the results.

Drawing from a large survey of parents administered by the U.S. Census Bureau, we found that 2- to 10-year-olds who spent four or more hours a day on portable electronic devices — versus no time — were twice as likely to be significantly sleep deprived. TV time was also connected to less sleep, but not as strongly or consistently.

Among teens ages 14 to 17, those who spent four or more hours a day on portable electronic devices – versus no time – were 44 percent more likely to not sleep enough. However, once portable device time was statistically controlled, watching TV or playing video games on a console had little link to sleep time.

Why would portable devices be more strongly associated with losing sleep?

For one thing, TV is simply not as psychologically stimulating as a portable device like a smartphone, which, unlike a TV, doesn't exist to simply consume media. Smartphones have also become a huge part of social life, whether it's texting with friends or interacting with them on social media.

And unlike TV, smartphones and tablets can be silently carried into the bedroom or even the bed, resulting in some teens using them throughout the night – what some call "vamping."

That might explain why sleep deprivation among teens spiked after 2012 – just as smartphone use became common.

The lesser of two evils?

To be clear, we did find that watching many hours of TV was associated with less sleep, especially among elementary-school age children. Watching over three hours a day of TV is also associated with depression — though more weakly than portable device use.

So parents were right to worry about kids watching too much TV in the 1970s and 1980s. But their worries might not have been as justified as today's parents' concerns about smartphones.

So what is a parent — or anyone who wants to sleep well — to do?

First, it's best for smartphones and tablets to stay out of the bedroom after "lights-out" time. Nor is it a great idea to use the devices within an hour of bedtime, as their blue light influences the brain's ability to produce melatonin. Finally, as a general rule, two hours a day or less spent on portable devices is a good guideline. These rules apply to parents, too – not only kids.

Just don't binge-watch TV instead.

Jean Twenge, Professor of Psychology, San Diego State University

This article is republished from The Conversation under a Creative Commons license. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

Among the most exciting moments during pregnancy is when a mother-to-be feels her baby move inside her. Now, research suggests that that kicking isn't just for kicks: With each kick and jab, your baby may be mapping out its brain and building an information superhighway.

These kicks, known as fetal movements, enable a baby to construct a basic brain network so that it can understand what part of the body is moving and how it is being touched, the researchers found.

This early spatial mapping lasts only until birth, when within just a few days, the very same types of movements no longer have the same effect on the brain. It is as if the movements in the womb are preparing the baby for life on the outside, providing the neural scaffolding upon which the brain will build layers of complexity with all the new kinds of sensory input in the world, the researchers suggested. [11 Facts Every Parent Should Know About Their Baby's Brain]

And the reward for feeling around within the womb is nearly instant.

"These fundamental aspects of touch are useful immediately from birth for skills like breastfeeding," said Kimberley Whitehead, a doctoral student at University College London (UCL), who co-led the study.

The study's findings may have implications for neonatal clinical care, such as how to wrap a very premature baby so that it can maintain that sense of being in the womb and further develop this basic brain network, said Whitehead and her dissertation adviser and study co-lead, Lorenzo Fabrizi, a senior research fellow at UCL.

The study is published today (Nov. 30) in the journal Scientific Reports.

Previous research conducted by others has found that spontaneous movements and consequent feedback seen just after birth are necessary for proper brain mapping in animals such as rats. Yet rodents are born in a premature state, less developed than newborn humans. For example, baby rats don't open their eyes until they are about 13 days old.

The question for Fabrizi was whether humans have the same early brain mapping before birth. And yet, researchers can't study the brain waves of babies still in the womb. [That's Incredible! 9 Brainy Baby Abilities]

So, Fabrizi's laboratory devised a study in collaboration with University College London Hospital to examine a variety of newborn humans, including those born premature. A total of 19 newborns, about 2 days old, on average, took part in the study; they were between 31 and 42 weeks in so-called corrected gestational age when studied. Corrected gestational age takes into account their age if they were still in the womb; a baby born at 35 weeks and being 1 week old, for instance, would have a corrected gestational age of 36 weeks.

Using noninvasive electroencephalography (EEG), the researchers measured brainwaves as these infants slept, focusing on the times when the newborns kicked their limbs during rapid eye movement (REM) sleep. And they found evidence for this building of brain networks, especially among the prematurely born babies.

For example, the movement of a baby's right hand caused brain waves to fire immediately afterward in the part of the left brain hemisphere that processes touch for the right hand. The size of these brain waves was larger (meaning a greater increase in activity) in premature babies, who at their age would otherwise still be in the womb, compared with the infants born full-term.

Whitehead said her team's most recent data, not yet published, suggests that other aspects of touch develop in the first several weeks after birth, such as combining information from both the left side and the right side of the body.

"These early patterns [developed in utero] lay out the pathways on which then experience after birth can work on to refine the initial map," Whitehead told Live Science.

For premature babies, the findings suggest that keeping a newborn swaddled or nested in a cot may be beneficial to allow the baby to feel a womb-like surface when he or she moves. Also, as these movements were observed during REM sleep, the results support the notion that sleep should be protected in newborns in hospitals with minimal disturbance for necessary medical procedures.

They are busy building their beautiful brains, after all.

• 18 Ways Pregnancy Changes Your Body Forever
• Are You Pregnant? 12 Early Signs of Pregnancy
• Why Are Pregnant Women Told To Sleep On Their Left Side?

Originally published on Live Science.

Follow Christopher Wanjek @wanjek for daily tweets on health and science with a humorous edge. Wanjek is the author of "Food at Work" and "Bad Medicine." His column, Bad Medicine, appears regularly on Live Science.

When kids catch a stomach bug, they are increasingly treated with probiotics in the hopes of improving the symptoms of diarrhea and vomiting. But rigorous new research finds that young children with intestinal infections don't appear to benefit from several commonly used probiotics.

Two large studies — one conducted in the United States and the other in Canada — found that preschool-age children with gastroenteritis had similar symptoms and recovery time, regardless of whether they were given probiotics or not.

"Because of the popularity of probiotics, it was important to make sure their use is worth the cost," Dr. David Schnadower, a pediatric emergency medicine physician who led the U.S. study at Washington University School of Medicine in St. Louis, said in a statement. "In this instance, probiotics added no measurable benefit, and, therefore, they are not worth the added cost." [Don't Be Fooled: 5 Probiotics Myths]

Both studies were published Nov. 21 in The New England Journal of Medicine.

Do probiotics really help?

Gastroenteritis — or intestinal inflammation caused by infections with viruses, bacteria or parasites — is a common ailment in young children, accounting for about 1.7 million pediatric emergency room visits in the U.S. each year.

Some studies have suggested that probiotics, or "good bacteria," can help kids with gastroenteritis, but many of these studies were small and not rigorously designed, the researchers said.

In the new U.S. study, nearly 1,000 children with gastroenteritis were randomly assigned to receive either the probiotic Lactobacillus rhamnosus GG (LGG) or a placebo, for five days. The children were ages 3 months to 4 years old, and visited the emergency room for symptoms of gastroenteritis, which can include watery stools, vomiting and diarrhea. The study took place in hospitals in 10 U.S. cities.

The study was a "double blind," which means that neither the patients (or the children's parents in this case) nor the researchers knew whether the children had received the probiotic or the placebo.

During the two-week study, children in the probiotic group fared about the same as children in the placebo group. For example, in both groups, symptoms of diarrhea cleared up after two days, and the children missed about two days of daycare.

"We tested many different scenarios — infants compared with toddlers, whether the patient had taken antibiotics, whether the gastroenteritis was caused by virus or bacteria, and how long the diarrhea had been going on before the treatment was given," said Schnadower, who is now the senior academic director of the Division of Emergency Medicine at Cincinnati Children's Hospital Medical Center. "Every time, we reached the same conclusion…[the probiotic] did not help."

The Canadian study, which was similar in design to the U.S. one and which involved nearly 900 preschool-age children, also found no benefit for another common probiotic that contains two strains of bacteria, Lactobacillus rhamnosus R0011 and L. helveticus R0052.

The researchers noted that they relied on the parents' reports of children's symptoms, and although parents were given diaries to record symptoms, the researchers cannot rule out the possibility that some of these reports were not entirely accurate.

The results also cannot necessarily be generalized to all probiotics on the market. But the findings add to recent research questioning the benefits of probiotics. For example, a recent study found that some people's guts appear resistant to probiotics, meaning the bacteria fail to successfully live in, or "colonize," their guts. But there may still be specific conditions and population groups that benefit from certain probiotics, the Canadian team said.

• 5 Ways Gut Bacteria Affect Your Health
• 9 Disgusting Things That the FDA Allows in Your Food
• 9 Weird Ways Kids Can Get Hurt

Originally published on Live Science.

A baby octopus the size of a pea was hitchhiking on a piece of plastic floating in the Pacific Ocean when Hawaiian researchers spotted it and scooped up the smol, smol cephalopod.

Photos shared on Facebook by Hawaii's Kaloko-Honokōhau National Historical Park show the wee baby rescued from the trash and huddled in a plastic tub, its spotted arms curled daintily under its bulging eyes and mantle.

In one of the park's images, the baby cephalopod is dwarfed by a marine biologist's fingertip; the octopus is too tiny to comfortably hug a human finger with all its arms. [8 Crazy Facts About Octopuses]

Park researchers were monitoring coral reefs in August when they spotted the charismatic eight-armed stowaway on a piece of floating plastic debris, park representatives wrote on Facebook. After posing for a few pictures, the octopus was released "safe and sound in a small protected space" by a member of the Geoscientists in Parks dive team, according to the post (an image of the octopus recently went viral after the U.S. Department of the Interior shared it on Instagram earlier this week).

Even though baby octopuses are small, they can also be deadly (to other very small creatures, that is). A second tiny octopus, also found on the plastic trash by the Hawaiian dive team, was discovered while squeezing the life out of equally tiny prey — a baby crab — prompting a park representative to pose the question: "Maybe they aren't so cute?"

The babies were likely day octopuses (Octopus cyanea) or night octopuses (Callistoctopus ornatus), two species that inhabit Hawaiian waters, Sallie Beavers, a marine ecologist with the park, told the Associated Press. Day octopuses can grow to have an armspan measuring about 3 feet (80 centimeters), while adult night octopuses can have an armspan measuring up to 7 feet (2 meters), according to the University of Michigan's Animal Diversity Web.

Octopuses are known for their intelligence, and their oddball biology is so unusual that it recently inspired a team of 33 researchers to report that octopuses were extraterrestrial in origin, their frozen eggs carried to Earth millions of years ago by icy comets. However, biologists scoffed at the prospect of alien octopuses — a hypothesis that has zero evidence to back it up, Live Science previously reported.

As one of the baby octopuses swam away from its human rescuers, it bid them farewell with a tiny squirt of ink, Beavers told the AP.

Originally published on Live Science.

Dozens of children across the United States have developed a rare polio-like illness, but the reason for this spike in cases remains a mystery, according to health officials.

Today (Oct. 16), the Centers for Disease Control and Prevention (CDC) announced it had received reports of 127 cases of people with the condition, called acute flaccid myelitis (AFM), in 2018. Of these, 62 cases have been confirmed in 22 states.

Most of these cases began in August and September, and 90 percent are in children, Dr. Nancy Messonnier, director of the CDC's National Center for Immunization and Respiratory Diseases, said at a news conference today.

AFM is a condition that affects the nervous system and causes muscle weakness, according to the CDC. In particular, the condition can cause weakness in the arms and legs along with loss of muscle tone and problems with reflexes. Other symptoms include facial drooping, difficulty moving the eyes, difficulty swallowing and slurred speech. [27 Oddest Medical Cases]

The condition is not new, but officials started to see a rise in cases in 2014; and there was another spike in 2016. So far, the number of cases in 2018 is similar to the number reported in 2014 and 2016, Messonnier said.

"We know this can be frightening for parents," Messonnier said. But she stressed that despite the increase in cases, the illness is still very rare, occurring in fewer than 1 in a million people in the U.S. each year. Still, if a child experiences sudden weakness or loss of muscle tone in their arms or legs, parents should seek medical care right away, she said.

However, officials have not been able to identify the cause of most of the AFM cases, or the reason for the spikes in 2014, 2016 and now 2018.

In a few cases, it appears that the illnesses were linked to viruses, including enterovirus. But officials haven't been able to find a single agent that would explain the clusters of cases that occur around the same time.

"[There's] nothing that provides the unifying diagnosis that we'd expect to explain these peaks of disease," Messonnier said.

And despite the resemblance to polio, officials have ruled out poliovirus as a cause of the illnesses.

Besides viruses, officials are also considering environmental toxins as a possible cause, but so far, they have no evidence that a particular toxin is behind the cases.

The outlook for patients with AFM can vary from a quick recovery to ongoing paralysis, Messonnier said. One child died from AFM in 2017.

Because officials don't know the cause of AFM, they can't recommend a specific way to prevent it. But Messonnier said that, in general, parents can help protect their children from diseases by washing their hands, making sure their children are up to date with vaccinations and applying insect repellent to protect against mosquito bites, which can spread viruses.

Originally published on Live Science.

More and more cases of a rare polio-like illness are being reported across the country, according to news reports.

In recent weeks, six cases of the illness, known as acute flaccid myelitis (AFM), have been diagnosed in children in Minnesota — a state the typically sees less than one case of AFM per year, according to the Minnesota Department of Health. On Tuesday (Oct. 9), a hospital in Pittsburgh said it is currently treating three children with suspected AFM, according to local news outlet KDKA. And yesterday (Oct. 10), the Illinois Department of Public Health said it had received recent reports of nine children diagnosed with the condition.

Also this week, the Colorado Department of Public Health and Environment announced that 14 cases of AFM have occurred in the state this year.

AFM is a condition that affects the nervous system and causes muscle weakness, according to the Center for Disease Control and Prevention (CDC). In particular, the condition can cause weakness in the arms and legs along with loss of muscle tone and problems with reflexes. Other symptoms include facial drooping, difficulty moving the eyes, difficulty swallowing and slurred speech, the CDC says. Most cases are in children.

The condition is not new, but officials started to see a rise in cases in 2014. Since then, more than 350 cases of the illness have been reported in the U.S. over a four-year period. So far this year, there have been 38 cases in 16 states, the CDC says.

The cause of AFM, and the reason for the rise in cases starting in 2014, is not known. However, the 2014 cases coincided with a national outbreak of a respiratory illness caused by a virus called enterovirus D68. It's possible that AFM has a variety of causes, including viruses (such as poliovirus and enteroviruses), environmental toxins and genetic disorders, the CDC says.

The condition is still very rare, occurring in fewer than one in a million people in the U.S. each year, the CDC says.

Originally published on Live Science.

Could the key to better gut health reside in a probiotic cocktail brewed from the contents of an infant's dirty diaper?

That's the question driving a new line of research investigating the power of baby poop as a potential source of microbes that could contribute to healthier digestion. And experiments recently showed that certain types of bacteria extracted from baby feces could promote the production of short-chain fatty acids (SCFA) in mice, and in a medium simulating the human gut.

SCFA molecules are a subset of fatty acids that are churned out by some types of gut microbes during the fermentation of fiber. They're associated with maintaining gut health and protecting against disease, so a probiotic containing baby-poop microbes could provide health benefits by boosting SCFA production in a compromised digestive system, researchers reported in the new study. [5 Ways Gut Bacteria Affect Your Health]

"Short-chain fatty acids are a key component of good gut health," lead study author Hariom Yadav, an assistant professor of molecular medicine at Wake Forest School of Medicine, said in a statement. "People with diabetes, obesity, autoimmune disorders and cancers frequently have fewer short-chain fatty acids. Increasing them may be helpful in maintaining or even restoring a normal gut environment, and hopefully, improving health," Yadav said.

Fecal microbiota transplants (FMT), or "poop transplants," can treat a type of gut disorder with an infusion of diverse bacteria from a healthy digestive system, distilled from a donor's poop. This helps to correct imbalances of microbial diversity when the gut microbiome is dominated by the bacteria Clostridium difficile (C. diff), which can lead to serious gut disorders. 

Previous studies have investigated the use of probiotics — those healthy gut bacteria — by testing their impact in guts already affected by disease, the researchers wrote in the study. For the new investigation, they wanted to see how a probiotic would impact SCFA production in a healthy gut. They chose to work with baby poop because infants' gut microbiomes are typically free from age-related diseases "such as diabetes and cancer," and because of the sheer abundance of infant feces at their disposal. ("Their poop is readily available," Yadav said.)

In the small, new study, the researchers isolated 10 bacterial strains — five species of Lactobacillus bacteria, and five species of Enterococcus — in samples from 34 babies, identifying the strains as good candidates for crafting a probiotic cocktail of microbes that could survive in a human host's gut and stimulate SCFA production, according to the study.

They then tested different doses of the 10-bacterial probiotic blend in mice, as well as in a slurry of human feces meant to mimic the environment of a human digestive system. The scientists found that even single doses maintained the healthy microbial balance and increased SCFA production in both the mice and the feces medium, the researchers reported.

"This work provides evidence that these human-origin probiotics could be exploited as [treatments] for human diseases associated with gut microbiome imbalance and decreased SCFA production in the gut," Yadav said.

Still, much more research is needed before you'll find baby-poop probiotics on the shelves of your health-food stores.

"Our data should be useful for future studies aimed at investigating the influence of probiotics on human microbiome, metabolism and associated diseases," Yadav said.

The findings were published online Aug. 23 in the journal Scientific Reports.

A newborn in England surprised her parents — and her doctors — when they saw that the infant was born with a tiny tooth, according to news reports.

The tooth was wobbly, so when little Isla-Rose Heasman was just 12 days old, her mother took her to a dentist, who put numbing cream on the baby's gum and promptly pulled the tooth out, the BBC reported.

While Isla-Rose's case is rare, the condition, known as a natal tooth, isn't unheard of, said Dr. Homa Amini, a professor of clinical pediatric dentistry at The Ohio State University College of Dentistry, who wasn't involved with Isla-Rose's case. [Chew on This: 8 Foods for Healthy Teeth]

A natal tooth is simply a baby tooth that erupts "very early," Amini told Live Science. But the phenomenon is a bit of a mystery to doctors. "It's really not known why it erupts that early," Amini noted.

Natal teeth happen in only about 1 in 2,500 births, said Amini, who is also a pediatric dentist at Nationwide Children's Hospital in Columbus, Ohio. In about 15 percent of cases, the baby's parents, siblings or close relatives also had a natal tooth, indicating that genetics plays a role, according to a 2012 review on natal teeth in the Indian Journal of Dentistry.

Most babies get their primary teeth, often the lower front teeth, beginning at 6 months of age, an event that "brings immense joy to the parents," the review's authors said. Natal teeth, however, aren't always seen so favorably. These teeth usually have little to no roots, so they're often wobbly and pose a risk to the child, who can mistakenly inhale or swallow the teeth. These teeth can also make breastfeeding difficult and can cut the baby's tongue.

In addition, these teeth are usually not pearly white. "The enamel in natal and neonatal teeth is normal for the age of the child," the review said. "But when the tooth erupts prematurely, the uncalcified enamel matrix wears off because mineralization is not complete. The tooth turns yellow-brown, and the enamel continuously breaks down."

So, doctors usually recommend that the tooth be pulled, just as it was in Isla-Rose's case. When this happens, the child won't grow another tooth in that spot until an adult tooth erupts, usually at age 6 or 7, Amini said.

But even though the child will miss this tooth for a few years, "it's not a problem. They just don't have a tooth down there," Amini told Live Science. "Nothing has been reported as causing long-term problems."

If natal and neonatal teeth are secure enough to stay (and if they're not causing any problems with nursing), they usually remain about 0.07 inches to 0.2 inches (2 to 5 millimeters) shorter than other baby teeth, according to the review.

Historically, natal teeth were seen either as lucky or ill-fated. The Roman historian Titus Livius (born 59 B.C) viewed natal teeth as a "prediction of disastrous events," while Pliny the Elder (born A.D. 23) thought "a splendid future awaited male infants with natal teeth, whereas the same phenomenon was a bad omen for girls," according to the review.

In the past, people in England thought that infants with natal teeth were destined to be famous soldiers, and France and Italy also considered the teeth a mark of good fortune. But in China, Poland, India and Africa, newborns with teeth were usually considered "monsters and bearers of misfortune," the review reported.

These days, whenever a baby's tooth comes in, it's important to take the child to the dentist. That way, parents can learn the best way to care for their baby's little chompers, Amini said.

Original article on Live Science.

The idea of using gene-editing technology to tweak a baby's DNA before birth has been the topic of fierce debate for years. But now, most Americans say using this technology on embryos would be acceptable under certain circumstances, according to a new poll.

The poll, from the Pew Research Center, found that 76 percent of Americans say that altering an unborn baby's genetic characteristics in order to treat a serious disease the baby would have at birth is an appropriate use of gene-editing technology.

In addition, 60 percent of Americans support the use of gene-editing technology in unborn babies to reduce the child's risk of developing a serious disease over his or her lifetime, the poll found.

However, only 19 percent of Americans say it would be appropriate to use the technology to make a baby more intelligent; the vast majority of Americans, 80 percent, say this would be taking the technology too far. [10 Amazing Things Scientists Just Did with CRISPR]

Once the realm of science fiction, gene editing for babies is getting closer to becoming a reality thanks to the development of the gene-splicing technology known as CRISPR, which allows scientists to precisely cut and insert pieces of DNA. In 2017, U.S. scientists announced that they had used CRISPR to edit genes in human embryos to correct a mutation that causes a heart defect. (The embryos were discarded, and they did not progress far in development.)

Still, there are many safety and ethical issues surrounding editing human genomes that have yet to be explored. Currently, the U.S. Food and Drug Administration doesn't allow clinical trials that involve editing the germ line, or making genetic changes that can be inherited, according to The New York Times.

It's likely that the development of gene editing will involve testing the technologies on human embryos (as the 2017 study did), but most Americans are averse to this idea: The Pew poll found that 65 percent of Americans say that if gene-editing development requires testing on human embryos, it would be taking the technology too far. (Only 33 percent of Americans say that it would be appropriate to test on human embryos to develop gene-editing technologies.)

The poll also found that Americans who are highly religious differ in their acceptance of gene editing compared with those who are less religious. For example, among the highly religious, 46 percent say it would be appropriate to use gene editing to reduce a baby's risk of disease later in life, while 53 percent say this would be taking the technology too far. Among the less religious, 73 percent say using gene editing to reduce a baby's risk of disease later in life would be appropriate, while only 27 percent say this would be taking the technology too far.

Interestingly, when asked to think about a future in which gene editing for babies is widely available, those surveyed tend to anticipate more negative effects over positive ones from the widespread use of the technology, the survey showed. Close to 60 percent of Americans say gene editing will "very likely" lead to increased inequality, because the technology will only be available for the wealthy. And a slight majority, 54 percent, say it is very likely that "even if gene editing is used appropriately in some cases, other people will use these techniques in ways that are morally unacceptable."

Only 18 percent say it is very likely that the development of gene-editing technologies will "pave the way for new medical advances that benefit society as a whole."

The survey is based on interviews with a nationally representative sample of more than 2,500 U.S. adults, conducted from April 23 to May 6.

Original article on Live Science.

Earlier this week, a study came to a surprising and heartbreaking halt. A Dutch drug trial looking into the effects of sildenafil — the generic version of Viagra — on a rare but serious fetal-development condition was cut short after 11 infants, born to mothers who had taken the drug while pregnant, died, The Guardian reported yesterday (July 24).

But why were pregnant women given the drug to begin with?

Although using a men’s erectile-dysfunction drug for pregnancy problems may sound unusual, the odd treatment — and investigations into how it can help this particular fetal-development condition — has actually been around for years. [7 Ways Pregnant Women Affect Babies]

Viagra is in the category of medications known as vasodilators, meaning it opens up blood vessels, increasing blood flow. The effect can give men a boost when they need more blood flow to a particular area. And under the set of conditions that the Dutch research team examined, boosting a pregnant woman's blood flow to the placenta could have really helped the fetus.

The trial was focused on pregnant women with fetuses that had a condition called early-onset fetal growth restriction. Simply put, the condition basically means there isn’t enough blood flow to the placenta, said Dr. Ahmet Baschat, the director of the Johns Hopkins Center for Fetal Therapy at the Johns Hopkins University School of Medicine. This can happen either because the mother’s blood vessels aren't providing enough blood to the placenta, or because the baby’s blood vessels can't generate healthy blood flow. Either way, the result is the same: The amount of oxygen and nutrients flowing to the fetus is very low.

The condition is rare — Baschat said he estimates that between 0.5 and 0.8 percent of pregnancies are affected — but serious. "[The placenta] loses ability to work way before due date," Baschat told Live Science, and mothers often give birth early, between 24 and 32 weeks. Only about 40 to 50 percent of those babies survive. (Indeed, among the women in the trial who were in the control group — meaning they didn't get the drug — nine of the babies died.)

But, every extra day that a baby remains in a healthy womb, Baschat said, adds an extra 2 percent likelihood of survival. "Nothing beats gaining gestational age," he said. So, if sildenafil were able to open up the blood vessels connecting mother and fetus and make sure the infant stayed in the womb longer, it could ease the consequences of a condition that's otherwise untreatable.

However, increasing blood flow to the fetus isn't the only reason a pregnant woman might take sildenafil. Dr. Uri Elkayam, a professor of cardiology and obstetrics and gynecology at the Keck School of Medicine at the University of Southern California, said that he prescribes sildenafil to expectant mothers with pulmonary arterial hypertension — a condition where blood pressure in the lungs is too high. Unlike fetal growth restriction, however, this lung problem can also occur in patients who aren’t pregnant. [Viagra Goes Generic: 5 Interesting Facts About the 'Little Blue Pill']

But “recently, management [of the condition in pregnant women] has included sildenafil, and in general, it has been useful,” Elkayam told Live Science. Along with a few other medications, sildenafil has prolonged the life expectancy of mothers with this pulmonary problem, though Elkayam said he suspects that until the exact reason behind the recent deaths seen in the study is figured out, its results will drastically change how he and other doctors prescribe the drug.  

Indeed, the exact reason is unclear. Baschat said that he is also curious to see what official conclusion the Dutch research team arrives at regarding the cause of these deaths. The study was part of an international investigation into how sildenafil could help with fetal growth restriction, and the prior research — also done in humans — found that the medication didn’t improve circumstances or extend how long the fetus was in the womb. That earlier research did conclude, however, that the drug was safe to give to pregnant women.

"The question I have is: If somebody does a trial and it shows a negative result, why would you then do another trial?" Baschat said. It might come to light that some other factors contributed to the surprising number of deaths in this study, but "ultimately, it’s important to share exact details — we need to know what happened," he said.

Originally published on Live Science.

The severely elongated head of a preserved skeleton found in Peru's Atacama Desert in 2003 is so unusual that it initially prompted people to suggest that the diminutive body was that of an extraterrestrial.

Since then, DNA testing confirmed that the remains — which measure about 6 inches (15 centimeters) long — belonged to a human fetus that researchers named Ata. But the scientists who conducted that investigation and published their findings in March have recently come under fire for their methods.

Yesterday (July 18), another group of researchers presented an evaluation of the earlier study, publishing an analysis in the International Journal of Paleopathology. They criticized the prior research, suggesting that its conclusions about the skeleton's so-called abnormalities — such as missing ribs — reflected an incomplete understanding of normal fetal development. That mistaken interpretation of the remains led the scientists to proceed with DNA extraction that damaged part of the skeleton. Their investigation, which did not include any Chilean researchers, may have sidestepped protocols that typically monitor the ethics of research conducted with human remains, as their publication omitted "a sufficient ethics statement or archaeological permit," Kristina Killgrove, co-author of the new study and an assistant professor of anthropology at the University of West Florida, wrote in an article for Forbes.

In the new paper, the authors pointed out that the mummy's unusual-looking skull and body were not necessarily the result of "anomalies," as the previous research suggested. Rather, the skull could have been elongated by vaginal delivery of the preterm fetus, while heat and pressure underground after the body was buried could have further compressed the cranium, the scientists reported. [Image Gallery: Odd Alien-Looking Skeleton Poses Medical Mystery]

The authors of the new analysis also questioned the earlier research's suggestion that "novel mutations" could explain the mummy's size. The authors noted that skeletal development at the fetus' suspected age, 15 weeks, would not have been affected by the genetic variants that the researchers described in the previous study.

Because the remains are thought to be just a few decades old, studying them raises ethical concerns that the March study did not adequately address, the scientists in the new study said. Furthermore, as DNA extraction can destroy some of the body's tissues, additional restrictions typically apply for such an examination. And it is unclear from the prior study that DNA sampling was required to begin with, the researchers said.

"Unfortunately, there was no scientific rationale to undertake genomic analyses of Ata, because the skeleton is normal," the authors wrote in the new study, adding that the whole-genome testing previously performed "was unnecessary and unethical."

"We caution DNA researchers about getting involved in cases that lack clear context and legality, or where the remains have resided in private collections," the study authors concluded.

Original article on Live Science.

Stare into a baby's eyes, and you might notice something odd: Babies rarely blink.

As numerous studies have documented, adults, blink about 15 times a minute, on average. But newborns and infants blink far less often — only a handful of times every minute, with some babies blinking as infrequently as once a minute.

"The average is two or three blinks a minute — so, decidedly low," said Leigh Bacher, a professor of psychology at the State University of New York at Oswego.

This may seem like just an odd little behavior, but researchers believe babies' blinks may hold insights about the mysterious brains of these tiny humans. [What Do Babies Dream About?] 

That's because blinking is regulated by the brain's dopamine, one of the neurotransmitters that allows brain cells to communicate. So, studying blinking in babies could help us better understand how this important neurotransmitter operates in little ones.

Studies have shown the link between dopamine and blinking, as conditions or drugs that affect dopamine also change blinking rates. People with schizophrenia, which may be caused, in part, by too much dopamine, blink more frequently. Conversely, in Parkinson's disease, which is caused by the death of dopamine-producing neurons, blinking is markedly decreased. Taking medication to raise dopamine levels brings blinking rate back up.

But dopamine also underlies a diverse set of other functions, from the control of movements and hormonal levels to learning and motivation. So, babies' blinking rates may reveal something about the development of the dopamine system and perhaps even reflect individual differences in some aspects of babies' nervous systems, Bacher said.

"Spontaneous blinks could be potentially useful clinically — as one additional source of information about neurobehavioral development," Bacher said. She cautioned, however, that a lot more research is needed to understand blinking in babies. [See One, Want One: The Roots of 'Baby Fever']

Why do we blink?

Spontaneous blinking is different from reflexive blinking, which serves to protect the eye from being poked by an external object, and from voluntary blinking, which we do on purpose.

Even in adults, the main purpose of spontaneous blinking is somewhat of a mystery. It's generally thought to spread tears over the surface of the eye to keep it lubricated while removing dust and other irritants.

But that's only one part of the story, researchers say. We blink more often than is necessary to keep the eyes wet, so blinking must have other functions as well.

Inquiry into the nature of spontaneous blinking goes a long way back. In 1928, two scientists in Scotland, Erik Ponder and W.P. Kennedy, conducted a comprehensive study of factors affecting the rate of spontaneous blinking in adults. In the absence of a video camera to reliably record eyeblinks, the scientists built a small apparatus out of silk thread, wood and a spring connected to an electrical circuit. They attached the device to the eyelids of participants. Whenever the participants blinked, their closing eyelids pulled on the spring and caused a break in the circuit, registering a signal.

As long as the conditions were kept the same, each person's blinking rate was like clockwork, the researchers found. The rate of blinking was the same in dark and well-lit rooms. Blind people blinked as often as sighted people did. And anesthetizing the surface of the eye didn't change blinking rate. [Why Do Babies' Eyes Start Out Blue, Then Change Color?]

The rate was also independent from humidity and drying of the eyes. When the researchers took their subjects to the humid houses of their university's botanical department, they found that blinking rates were no different from those of people the scientists had observed in the dry sauna rooms of various Turkish baths.

But blinking rate always increased in tandem with the "mental tension" of the study participants, Ponder and Kennedy found. For example, study participants blinked more when they were excited or angry, and witnesses in law courts blinked faster when they were being questioned by the opposing party, the scientists found.

All of this led Ponder and Kennedy to suggest that spontaneous blinking is not governed primarily by the condition of the eyes, but instead by a "blinking center" in the brain. The researchers proposed that one function of blinking is to relieve tension, in a manner similar to fidgeting and the nervous movement of fingers.

Modern studies have come up with more ideas about why we blink. According to one hypothesis, the brain takes a moment of rest when we blink. In a 2012 study published in the journal Proceedings of the National Academy of Sciences, researchers monitored the brain activity of a group of people watching the TV show "Mr. Bean." The brain scans revealed that when people blink, brain activity spikes in the "default mode network," which constitutes a group of brain regions most active when we are awake but resting and the mind is disengaged from the outside world.

Another study, published last year in the journal Current Biology, suggested that blinking focuses our gaze. "Our eye muscles are quite sluggish and imprecise … our findings suggest that the brain gauges the difference in what we see before and after a blink and commands the eye muscles to make the needed corrections," study researcher Gerrit Maus, an assistant professor of psychology at Nanyang Technological University in Singapore, said in a statement.

What does this all mean for babies?

Because one function of blinking is to keep the eyes lubricated, researchers have proposed that babies blink less than we do because their small eyes don't need as much lubrication.

Another idea is that infants, with their brand-new vision, have to work hard to get all the visual information they need. "When you do visually or attentionally demanding things, you tend to blink less," Bacher said. A similar phenomenon is seen in adults with computer vision syndrome, a condition in which the high visual demands of computer viewing cause reduced blinking and lead to dry eyes.

And then there's the dopamine system. Some researchers have suggested that the reduced blinking rate in newborns is due to an underdeveloped dopamine system. [Why Are 'Mama' and 'Dada' a Baby's First Words?]

"I don't think any of these are mutually exclusive," Bacher said.

Bacher and her colleagues conduct studies to find what they can learn about babies by measuring their eyeblinks. Compared to brain imaging and other techniques, eyeblink is a weak measure, but it's a noninvasive one, she said. Could it serve as a measure of dopamine activity? If so, it might help predict individual differences in personality, cognitive abilities, and the risk for dopamine-related conditions like attention deficit hyperactivity disorder (ADHD) or even Parkinson's disease later in life. These are all still speculative, Bacher said, but worth investigating.

"Seeking markers early in development for later emerging disease is going to be more and more valuable," Bacher said. "It will take a lot of good detective work to figure out what to look for, though."

Original article on Live Science.

The first time a pregnant woman feels her baby kick can be surprising — a sudden reminder that the tiny creature growing inside her has a mind of its own. But why do babies kick?

Though the womb is a tight space in which to exercise, it turns out that those kicks are vital for the baby's healthy bone and joint development, an expert told Live Science.

Fetuses begin moving in the womb about as early as 7 weeks, when they slowly bend their necks, according to a review paper published in the journal Ultrasound in Obstetrics & Gynecology. As the babies grow, they gradually add more movements to their repertoire, such as hiccupping, arm and leg movements, stretching, yawning, and thumb sucking. But the mom won't feel the bigger movements — such as kicks and punches — until 16 to 18 weeks into her pregnancy, when the baby is a bit stronger. [In Photos: How Babies Learn]

Babies need their exercise, too

An entire field of research is dedicated to figuring out whether the baby is in control of its movement or if those movements are just a reflex, said Niamh Nowlan, a bioengineer at Imperial College London. "Early movements are likely to be purely reflex," Nowlan told Live Science in an email, but as the movements become more coordinated, "it's likely the brain is in control of how much and when the baby moves." (Reflexes, on the other hand, come from the spinal cord and don't require input from the brain.)

Scientists may not know for sure if the movements are voluntary or involuntary, but Nowlan said the research is clear that movement is important. "The baby needs to move [in the womb] to be healthy after birth, particularly for their bones and joints," she said. In a review she published in the journal European Cells and Materials, Nowlan described how a lack of fetal movement can lead to a variety of congenital disorders, such as shortened joints and thin bones that are susceptible to fracture.

For pregnant women wondering if their baby is too kicky, or not kicky enough, Nowlan said there's no established amount of normal fetal movement during pregnancy. "Pregnant women are told to look out for significant changes in movements, which is quite vague advice, but it's the best that can be given at the moment," she said.

That's because it's difficult for scientists to study fetal movements, because the only way to measure them is in the hospital and it can be done for only a short period at a time. To get around this problem, Nowlan and her colleagues are working on developing a fetal-movement monitor that the mother can wear during her normal daily activities. The researchers tested the monitor on 44 women who were 24 to 34 weeks pregnant and could accurately detect breathing, startle movements and other general body movements. Their results were published in the journal PLOS One in May.

One study, published in 2001 in the journal Human Fetal and Neonatal Movement Patterns, found that boys may move around more in the womb than girls. The average number of leg movements was much higher in the boys compared to the girls at 20, 34 and 37 weeks, that study found. But the study's sample size was small, only 37 babies, so Nowlan and her colleagues are hesitant to claim there's a relationship between gender and fetal movement. 

Fetal kicks can pack a punch

It's unlikely that each woman will feel the same thing when her baby starts kicking.

"Different women experience the sensation quite differently, and sensations can vary between pregnancies," Nowlan said. In her own two pregnancies, for example, she said she was much more sensitive to the movements of her second child compared to those of her first. "I could always tell where my son's feet were, whereas that wasn't really the case for my first," she said. She hypothesized that this variation could have arisen because the womb muscles are more stretched out after the first pregnancy, a topic she's now studying.

The most-pronounced movements mothers will feel are the baby's kicks. A recent study from Nowlan and her colleagues, published in the Journal of the Royal Society Interface in January, found that the impact of the baby's kick increases from 6 lbs. (2 kilograms) of force at 20 weeks to 10 lbs. (4 kg) of force at 30 weeks. After that point, the baby's kick force decreases to just under 4 lbs. (2 kg). The scientists said they suspect the decrease in movement occurs because there is less room for the baby to move around.

But babies in the womb are doing more than just kicking. By 15 weeks, the baby is also punching, opening and closing its mouth, moving its head, and sucking its thumb. A few weeks later, the baby will open and close its eyes. But the mother will feel only the major movements: kicking, punching and maybe big hiccups.

The babies also do "breathing movements,'" said Nowlan. While the baby isn't actually breathing air, it will perform the same movement, just with amniotic fluid. Nowlan explained that babies who don't perform this movement often have trouble breathing once they're born, because they haven't built up their chest muscles.

Feeling a baby moving and kicking in the womb might be a weird sensation, but it's simply a sign of healthy development.

Original article on Live Science.

When Freddie Mercury sang, "Mama, life had just begun," in the second verse of "Bohemian Rhapsody," he probably didn't have an audience of fetuses in mind. Let's consider it a happy coincidence, then, that unborn babies really do seem to love Queen.

According to a new, as-yet-unpublished study by the Institut Marquès assisted-fertility clinic in Spain, fetuses exposed to "Bohemian Rhapsody" — as well as classic jams by Bach and Mozart — showed clear signs of mental stimulation in the womb. Songs by Shakira and the Bee Gees, on the other hand, proved much less interesting to the unborn audience.

Developing babies begin to hear external sounds at a gestational age of about 16 weeks, which is —it's safe to say — far too soon to have read an issue of Rolling Stone. So why should fetuses be such discerning music critics? According to the researchers, it might have something to do with the pitch of the song's sounds or the simplicity of the melody. [That's Incredible! 9 Brainy Baby Abilities]

"The first language was more musical than verbal," Dr. Marisa López-Teijón, director of the Institut Marquès, said in a statement. "We still tend instinctively to speak [to newborns] in a high-pitched voice, because we know that newborns perceive those better, and this way they understand that we want to communicate with them." (Interestingly, fetuses in the study also showed a greater response to Mickey Mouse's voice than to recordings of a normal human voice.)

"I'm big in the womb."

In the new study, which was presented this month at the International Association for Music and Medicine conference in Barcelona, Spain, researchers blasted a variety of tunes for 300 fetuses between 18 and 38 weeks of gestation.

Using a special intravaginal speaker (babies can't hear much through the mom's abdominal wall), the team played 15 songs for each fetus, ranging from sonatas by Bach and Beethoven, to traditional Spanish Christmas carols, to the hits of Queen, Adele and the Village People.

While the fetuses listened, the researchers watched for mouth and tongue movements on an ultrasound machine. They hypothesized that the babies who moved their mouths or tongues in response to the music were having the language centers of their brains stimulated and perhaps were learning to communicate back.

"Our initial hypothesis suggests that music creates a response which manifests as vocalization movements as it activates the brain circuits that stimulate language and communication," the researchers wrote on their website.

Overall, the fetuses seemed more stimulated by classical music than pop or rock. Ninety-one percent of the babies showed mouth movements, and 73 percent stuck out their tongues when Mozart's "A Little Night Music" played. Melodies by Bach, Prokofiev and Strauss all got more than 80 percent of the fetuses flapping their itty-bitty gums.

More than 80 percent of the fetuses responded to traditional drumbeats from Africa, a mantra from India and a Christmas carol from Spain. When it came to pop, however, the burgeoning critics were far more discerning. Their favorite song was, of course, "Bohemian Rhapsody" (90 percent of babies moved their mouths, and 40 percent stuck out their tongues), followed by the Village People's "Y.M.C.A."

Songs by Adele, the Bee Gees and Shakira impressed 60 percent or less of the fetuses.

These results jibe with those of previous studies that have linked classical music (played outside the womb, not intravaginally) to infant stimulation. However, if the findings don't jibe with your personal taste in music, don't sweat it too much. Mouth and tongue movements are rare in the second and third trimesters of pregnancy, the researchers wrote, so the bottom line is that any musical stimulation is more than most babies are used to.

Besides, fetuses can't hear much over the constant noise of their mothers' hard-working bodies, anyway. The real musical education begins after birth — you know, when baby is really able to rock out.

Originally published on Live Science.

Newborn babies are often depicted with a rather incongruous creature: a long-legged, sharp-beaked bird known as a stork. The image of this bird — usually with a cloth bundle dangling from its beak — has become so intertwined with infants that we barely question the stork's ubiquitous presence on well-wishers' cards, baby clothes and blankets.

But what's actually behind this association between storks and babies?

Like any myth, its origins are hard to trace, especially since this one spans the globe, appearing in folklore from Europe, the Americas, North Africa and the Middle East. The array of similar myths suggests that they all draw common inspiration from the birds' most noticeable features. [Why Are Human Babies So Helpless?] 

"The birds are big and white — linked to purity — and their nests are large, prominent and close to where people live. So, their good parenting behavior is highly evident," explained Rachel Warren Chadd, co-author of "Birds: Myth, Lore and Legend" (Bloomsbury Natural History, 2016).

Many popular accounts trace the myth back to ancient Greece and the story of a vengeful goddess named Hera. According to this story, Hera grew jealous of a beautiful queen named Gerana and transformed her into a stork. The heartbroken Gerana then sought to retrieve her child from Hera's clutches, and the Greeks depicted the transformed bird with a baby dangling from its beak.

But, when doing research for her book, Warren Chadd discovered that the original myth actually describes the baby-snatching bird as a crane, not a stork. "It can be difficult to verify that one species is associated with an ancient myth as, for instance, storks, cranes and herons were often confused," Warren Chadd told Live Science. Similarly, in Egyptian mythology, storks are associated with the birth of the world. But historically, that legendary creature was actually a heron: "A small stretch of imagination might make that a stork," Warren Chadd said.

Paul Quinn, a lecturer in English literature at the University of Chichester in the United Kingdom and editor of a research journal about folklore and fairy tales, speculated that the link between storks and babies may boil down to this species confusion. "I think the connection of the stork with infants, particularly maternal care of children, is the result of the conflation of the stork with the pelican," he told Live Science. European medieval literature associates the stately white pelican with Catholicism, rebirth and the rearing of young, he said. Somewhere along the way, storks may have become a substitute for this bird.

[See One, Want One: The Roots of 'Baby Fever']

9-month migration

Whatever the origins of the myth, historians tend to agree that the idea of the baby-bringing stork was most firmly established in northern Europe, particularly Germany and Norway. During the Pagan era, which can be traced back at least to medieval times more than 600 years ago, it was common for couples to wed during the annual summer solstice, because summer was associated with fertility. At the same time, storks would commence their annual migration, flying all the way from Europe to Africa. The birds would then return the following spring — exactly nine months later.

Storks "would migrate and then return to have their chicks in spring around the same time that a lot of babies were born," Warren Chadd said. Thus, storks became the heralds of new life, spawning the fanciful idea that they had delivered the human babies. [Why Pregnancy Really Lasts 9 Months]

As the story evolved over time, its complexity grew. In Norse mythology, storks came to symbolize family values and purity (based largely on the inaccurate belief that these birds were monogamous). In the Netherlands, Germany and eastern Europe, storks nesting on the roof of a household were believed to bring good luck — and the possibility of new birth — to the family below, Warren Chadd wrote in her book.

Although Europe was the epicenter of the myth, it took shape in the Americas too, she told Live Science. "It is interesting that the same story occurs in Sioux legend with a different type of stork, the wood stork [Mycteria americana], as opposed to the white stork [Ciconia ciconia]," she said. "They all arise from different people's observation of behavior wherever storks — particularly white storks — can be found."

Then, in the 19th century, the myth gained new traction as a symbol of birth, when it was popularized by Hans Christian Andersen in his version of the fable, called "The Storks." In this tale, these birds plucked dreaming babies from ponds and lakes, and delivered them to deserving families. The story had a dark underside, however: Families with ill-behaved children would receive a dead baby as punishment from the stork.

The tale sought to teach children a moral lesson and also kept with the new tradition of "'infantilizing' fairy tales — the growth of a specific literature for children, frequently didactic and religious in intent," Quinn said.

In Victorian England, the story became especially valuable as a way of obscuring the realities of sex and birth. "For Victorians embarrassed about explaining the facts of life, the stork bringing a baby was a useful image — modesty to the point of prudishness," Warren Chadd said.

Views on childbirth may be less prudish today, but we still hang on to the stork myth, celebrating the graceful bird and its central role in family life. "People love stories," Warren Chadd said. Our tendency to humanize animals has made the baby-delivering stork one of our most enduring myths, she added, "loosely based on the birds' behavior but also rooted in human hopes and fears."

Original article on Live Science.

The number of babies being born in the United States continues to fall, with the birth rate reaching a new record low in 2017, according to a new report from the Centers for Disease Control and Prevention.

Last year, about 3.8 million babies were born in the U.S., which is 2 percent lower than the number born in 2016, and the lowest recorded number of births in 30 years, according to the report.

What's more, there were about 60 births per 1,000 women ages 15 to 44, which is 3 percent lower than the rate in 2016, and the lowest recorded rate since the government started tracking birth rates in 1909. [7 Baby Myths Debunked]

The decline in the U.S. birth rate from 2016 to 2017 was the largest single-year drop since 2010, the researchers wrote in the report, which was published today (May 17).

The teen birth rate fell 7 percent from 2016 to 2017, to a rate of 19 births per 1,000 teens ages 15 to 19. In addition, birth rates generally declined for women under 40, reaching record lows among women in their 20s, the report authors found.

Part of the reason for the decline in U.S. birth rates may be that people are in a general state of economic uncertainty, said Karen Benjamin Guzzo, associate director of the Center for Family & Demographic Research at Bowling Green State University in Ohio. Even though the Great Recession technically ended in 2009, people may still feel uneasy about their economic situation; they may be employed but working part time, or going to school and working, or trying to pay off student loans, Guzzo said.

"People feel just really uncertain about the future," Guzzo told Live Science. "And that generally does not bode well for having kids."

In addition, young adults may feel like they haven't met all the milestones they feel they need to reach before having a kid, such as getting a college degree, having a stable income and getting married. "It takes longer to feel like you're a grown-up," Guzzo said.

One age group — women in their early 40s — did see an increase in their birth rate in 2017, the report found. This may be because this age group doesn't have a lot more time to wait to have kids. "They can't put it off for the future," Guzzo said.

Guzzo noted that the new report looked at overall births but didn't examine "birth order" — that is, whether the births were a woman's first, second or third child, and so on. So it's unclear from the current report whether women are having fewer kids overall (firstborns) or having smaller families; previous data suggested that the latter may be the case, Guzzo said. The CDC will examine birth-order data for 2017 in a follow-up report.

Original article on Live Science.

A man in Australia helped save the lives of more than 2 million babies by donating his "special" blood, which was used to make a medication that can prevent life-threatening problems in newborns. But why exactly is this man's blood special, and how does the medication work to save babies?

The 81-year-old man, James Harrison, donated blood for 60 years and made his final donation on Friday, May 11, according to the Australian Red Cross Blood Service. Sometimes called "the man with the golden arm," Harrison donated blood more than 1,100 times, and it's estimated that his donations helped save the lives of 2.4 million babies in total, the Australian Red Cross said.

Harrison's blood contains a rare antibody that's used to make a medication called anti-D immunoglobulin, also known as Rh immunoglobulin. This medication is given to mothers who are at risk for something called "Rh incompatibility" with their fetus, which means the mothers' immune system may attack and destroy the fetus's red blood cells.

When this happens, "you end up with a situation where a lot of these babies would have a significant amount of their red cells broken down while they were in the womb," said Dr. Saima Aftab, medical director of the Fetal Care Center at Nicklaus Children's Hospital in Miami. This can lead to serious complications for the newborn, including brain damage, jaundice or even stillbirth, Aftab said.

However, treatment with Rh immunoglobulin, which is made from the blood plasma of "special" blood donors like Harrison, can prevent these complications.

"The discovery of this antibody is one of the biggest life-saving discoveries of the last century," Aftab told Live Science. [7 Baby Myths Debunked]

How it works

You've probably heard that your blood type is "positive" or "negative." This refers to a protein called the "Rh factor" on the surface of red blood cells. When people have this protein, they are said to be "Rh positive," whereas if they lack the protein, they are "Rh negative."

For most people, whether they are Rh positive or Rh negative won't make a huge difference in their lives, Aftab said. But for pregnant women, there can be problems when the mother is Rh negative but the fetus is Rh positive.

That's because if the baby's Rh-positive blood cells leak into the mother's bloodstream, the mother's immune system sees the Rh-positive blood cells as "foreign" and makes antibodies again them, Aftab said. These antibodies can then cross the placenta and break down the fetus's red blood cells. In the developing world, such Rh incompatibility is one of the leading causes of illness and mortality in newborns, Aftab said.

To prevent problems from Rh incompatibility, doctors first test a woman's blood early in pregnancy or before pregnancy. If she is Rh negative, she'll likely be given Rh immunoglobulin. In the United States, about 15 percent of the population is Rh negative, according to Medscape.

The American College of Obstetricians and Gynecologists (ACOG) recommends that Rh-negative women receive this medication when they are 28 weeks pregnant and also within 72 hours after giving birth to an Rh-positive baby. A dose of Rh immunoglobulin may also be needed after invasive procedures, such as amniocentesis, or after a first-trimester miscarriage or abortion, ACOG says. In Australia, about 17 percent of pregnant women receive the treatment, including Harrison's own daughter, the Sydney Morning Herald reported.

Exactly how Rh immunoglobulin works to prevent complications from Rh incompatibility is not clear. But researchers think that the antibody covers the surface of the fetus's Rh-positive blood cells in the mother's bloodstream and prevents the mother's immune system from seeing them, Aftab said.

It's not common for people to have the type of antibody in their blood that's used to make Rh immunoglobulin. Indeed, in Australia, the country's Rh immunoglobulin is made from a pool of only about 200 blood donors, according to the Australian Red Cross.

Harrison likely developed the antibody when he was given a large blood transfusion at age 14. Following that transfusion, "his immune system revved up a high concentration of antibodies" against Rh-positive blood cells, said Aftab, who has not treated Harrison. This would mean that Harrison himself is Rh negative.

Harrison needed to stop donating blood because he is past the age limit for blood donors in Australia, and the Australian Red Cross said he should stop donating to protect his health, according to the Sydney Morning Herald.

Original article on Live Science.

When Amelia Eldred, an active 7-year-old in England, needed her leg amputated to treat bone cancer, doctors performed an unusual surgery: They removed the middle part of her leg and then reattached the lower part of her leg — but backward.

While the surgery sounds odd — it results in a foot that's at knee height, facing the back of the body — doctors say it can allow children to have a more active lifestyle and better leg function, compared with other treatment options, such as a full-leg amputation. In this case, Amelia's backward foot acts as a knee joint.

"Straight away, it was the best option for us," Amelia's mom, Michelle Eldred, told the BBC. With a lower-leg prosthesis, the girl will be able to do all the things she loves to do, including dancing and sports. But with a full-leg amputation, she would be unlikely to have a good range of movement, Eldred said. [27 Oddest Medical Cases]

Rare procedure

The surgery that Amelia received is a rarely performed procedure known as rotationplasty, which is used to treat bone tumors that occur near the knee, according to the Dana-Farber/Boston Children's and Blood Disorders Center. In this case, Amelia was diagnosed with osteosarcoma, the most common type of bone cancer in children, which caused an aggressive tumor in her left femur (thighbone), according to the British news outlet Birmingham Live.

In an operation of this type, doctors first remove the middle section of the leg, which includes the bottom of the femur, the knee and the upper tibia. Then, they take the remaining portion of the lower leg, rotate it 180 degrees and reattach it to the femur. The foot is turned backward, so it can function as a knee joint, according to Dana-Farber/Boston Children's.

With a prosthesis attached over the foot, the patient's leg essentially functions as it would with a below-the-knee amputation, said Dr. Joel Mayerson, an orthopedic oncologist at The Ohio State University Comprehensive Cancer Center who was not involved with the case. That's important, because with an above-the-knee amputation, patients need to expend about 70 percent more energy than normal to walk with a prosthesis, but with a below-the-knee amputation, the energy expenditure is just 20 percent above normal, Mayerson said.

"This is a good alternative to allow them to be very functional with modern prosthesis use," Mayerson told Live Science.

Rotationplasty is most often performed on children under age 12, who are generally better at retraining their brains to use their ankle as their knee joint, according to Dana-Farber/Boston Children's. In addition, young children still have a lot of growing to do, which can make other treatment options for bone cancer more challenging.

For example, a procedure called limb-salvage surgery can be used to treat osteosarcoma, but that technique requires doctors to replace a section of the patient's bone with a metal implant or a cadaver bone. These materials don't grow with the child, though, so a young child will need multiple surgeries to make the limb longer so that it can grow with the child, Mayerson said. In contrast, with rotationplasty, "most of the time, it's one surgery, and you're done," he said.

Another advantage of rotationplasty is that it allows children to maintain a very active lifestyle, including allowing them to participate in high-impact activities, such as running and jumping, which wouldn't be possible with limb-salvage surgery, Dana-Farber/Boston Children's said. Patients who have rotationplasty also avoid the phantom limb pain that typically occurs with a traditional amputation, according to Stanford Children's Health, because the nerves in the lower leg are preserved.

Amelia was diagnosed with osteosarcoma in August 2017 and had several chemotherapy treatments before undergoing the rotationplasty surgery in January, according to Birmingham Live. A recent scan shows that Amelia's bones are fusing together well following the operation, Birmingham Live reported.

Amelia "has shown real bravery and confidence in showing off her leg, even though it looks a bit different," Dr. Lee Jeys, a consultant orthopedic surgeon at the Royal Orthopaedic Hospital in Birmingham, England, who performed the procedure, said in a statement. "I'm glad that she'll be able to continue doing all the things a normal child can do, including sports and dancing."

Original article on Live Science.

The percentage of kids with autism in the United States continues to rise, according to a new report from the Centers for Disease Control and Prevention (CDC).

The report found that, in 2014, an estimated 1 in 59 children had autism, up from 1 in 68 children in 2012, and 1 in 88 children in 2008. The findings are based on data from more than 300,000 8-year-old children living in 11 diverse communities across the United States.

A previous CDC report, released in 2016, suggested that the autism rate, or prevalence, was leveling off, but the new report shows that this is not the case.

"It is now clear that what we saw in 2016 was just a pause along the way. It remains to be seen at what point [autism spectrum disorder] rates will plateau," Walter Zahorodny, an associate professor of pediatrics at Rutgers New Jersey Medical School and a co-author of the report, said in a statement.

Autism spectrum disorder is a neurodevelopmental condition that affects communication, behavior and the ability to interact with others.

So what's behind the increase? Perhaps, rather than more kids having autism, just more of them are being diagnosed with it. Communities are doing a better job of diagnosing autism among minority populations, said Alison Singer, president and co-founder of the Autism Science Foundation, who was not involved in the new report.

Historically, autism prevalence has been much higher among white children compared with black and Hispanic children, according to the CDC. But in the most recent report, minority populations had similar percentages of kids with autism as found in white children, Singer said. (For example, in earlier years, autism rates were about 30 percent higher in white children than in black children; but in the latest report, the autism rate was only 7 percent higher among white children than in black children, the CDC said.)

This is a positive step, but the new report also revealed room for improvement in autism diagnoses, Singer said. For example, in 85 percent of the autism cases, there were notations in the children's health or educational records expressing concern about their development by the time they were 3 years old, but only 42 percent of the children received a developmental evaluation to diagnose autism by that age.

"Children are just not being diagnosed as early as they can be," Singer told Live Science. (An experienced professional can diagnose autism in a child by age 2; and in some cases, autism can be detected at 18 months or younger, according to the CDC. The American Academy of Pediatrics recommends all children be screened for autism at both 18 months and 24 months.)

This lag between when a parent, teacher or another person expresses concern about the child's development and the actual evaluation is problematic, because it affects when a child can begin interventional services for autism, Singer said. And the earlier a child starts these interventions, the better the prognosis, she said.

The new report used data from the CDC's Autism and Developmental Disabilities Monitoring Network (ADDM), a program that estimates autism prevalence based on reviews of children's health and education records when they are 8 years old. The ADDM is not a nationally representative sample of the United States, but it is one of the largest programs to monitor autism, and the only autism-tracking program that examines health and education records, the CDC said.

"It's really the gold standard of prevalence studies" for autism, Singer said.

The rate of 1 in 59 children (1.7 percent) with autism is the combined estimate for the 11 communities, which were in Arizona, Arkansas, Colorado, Georgia, Maryland, Minnesota, Missouri, New Jersey, North Carolina, Tennessee and Wisconsin. However, estimates varied widely among these 11 communities, from a low of 1 in 76 (1.3 percent) in Arkansas, to a high of 1 in 34 (1.9 percent) in New Jersey.

Some of these differences might be due to how autism is being diagnosed and documented in those areas, the CDC said.

Original article on Live Science.

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

Today, roughly one in five women in the U.S. doesn't have children. Thanks in part to this decline in birthrate, for the first time in U.S. history, there may soon be more elderly people than children.

Based on trends in costs, it's evident why many families are choosing to have fewer children – or in some cases, no children at all.

The cost of having children in the U.S. has grown exponentially since the 1960s, when the government first started collecting data on childhood expenditures. Between 2000 and 2010, the cost shot up by 40 percent.

As of 2015, American parents spend, on average, US$233,610 on child costs from birth until the age of 17, not including college. This number covers everything from housing and food to childcare and transportation costs. As a mother myself, as well as a sociologist who studies families, I have experienced firsthand the unexpected costs associated with having a child.

This spike costs has broad implications, affecting everything from demographic trends and human capital to family consumption.

Labor and delivery

The overall costs of labor and delivery vary from state to state.

Expenses for a delivery can range from $3,000 to upwards of $37,000 per child for a normal vaginal delivery and from $8,000 to $70,000 if a C-section or special care is needed.

These costs are often a result of separate fees charged for each individual treatment. Other factors include hospital ownership, market competitiveness and geographical location.

It's worth noting that these costs often include additional fees for ultrasounds, blood work or high-risk pregnancies.

As a result, for women who are concerned about the costs related to giving birth, it's important to explore the average costs at their local hospitals and review their insurance plans before they decide to become pregnant.

Childcare and activities

The U.S. Department of Health and Human Services deems childcare affordable if no more than 10 percent of a family's income is used for that purpose. However, parents currently spend 9 to 22 percent of their total annual income on childcare, per child.

Childcare has become one of the most expensive costs that a family bears. In fact, in many cities, childcare can cost more than the average rent. This is particularly challenging for low-income families who often do not make more than minimum wage.

What's more, over the past century, Americans significantly shifted in the way that we see childhood. Whereas, in the past, children often engaged in family labor, now children are protected and nurtured.

Yet children's activities can be costly. For example, Americans families will spend on average $500 to $1,000 per season on extracurricular or sports activities for each of their children.

In fact, due to the rising costs of sports, the number of children who aren't physically active has increased to 17.6 percent. Being physically inactive is even more likely for low-income children, who are three times less likely to participate than children who reside in higher-income households.

Another hidden cost associated with having a child is that of time. In my experience, many parents do not realize how much time they will invest in their children, often at the cost of personal freedom and work expectations.

In fact, the American Time Use Survey shows that, on average, parents with children under the age of 18 spend about 1.5 hours per day on domestic and childcare responsibilities. Women spend 2.5 hours a day, while men spend roughly only one hour on these tasks.

Weighing the causes

Researchers at Pew argue that the recent decrease in birthrate has as much to do with the Great Recession in 2008 as it does with the increase of women who are not willing to sacrifice their careers for family.

This speaks to yet another cost of having children: Mothers are often pushed out of careers or "opt out," based on high demands of balancing family and work-life balance.

Researchers have also found a growing trend of men and women who become single parents by choice. This group of parents prioritize children over marriage and often are on single incomes. That also contributes to the reduction in overall childbirth, from a financial and practical perspective.

Ultimately, the decision to have a child is a personal one. The data show that the burden of costs and the stress of family life are real. Yet, despite the costs associated with having a child, many parents report overall satisfaction with their marriage and family life.

Considering the high costs of having of a child, coupled with the tension in balancing family-work life matters, states and companies are starting to invest in family support policies, parental benefits and competitive education. And individuals are creating more innovative approaches to managing family-work balance, such as a reduction in working schedules, family support and a push for more shared responsibilities within the home.

Heidi Steinour, Visting Instructor in Sociology, University of South Florida

This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

This will take the fun out of bath time: A new study finds that rubber ducky toys are teeming with bacteria and fungi.

In the study, the researchers analyzed the microbes growing inside 19 real bath toys, taken (with permission) from households where the toys had been well-loved. The scientists also set up some controlled experiments, in which they started with new bath toys and subjected them to various conditions. Some of these new bath toys were periodically placed into a bath with clean water, while others were placed in "dirty" water after a bath.

The results were pretty gross. Upon dissecting the bath toys, the researchers found "dense and slimy biofilms" on the objects' inner surfaces. The toys contained between 5 million and 75 million bacteria cells per square centimeter. [6 Superbugs to Watch Out For]

The researchers also found fungi species in 60 percent of the real bath toys and in all of the "dirty water" toys.

Exactly which bacteria or fungi appeared, and their abundance, tended to vary from household to household, the study said. But overall, the researchers found potentially harmful bacteria — including Legionella and Pseudomonas aeruginosa — on 80 percent of the toys studied.

"Moldy bath toys are widely discussed in online forums and blogs, but they have received little scientific attention to date," senior study author Frederik Hammes, of the Department Environmental Microbiology at the Swiss Federal Institute of Aquatic Science and Technology, said in a statement. In fact, these toys are interesting for researchers, because they represent "the junction between potable water, plastic materials, external contamination and vulnerable end-users," meaning children, Hammes said.

However, whether the bacteria and fungi found on bath toys are harmful to children is unclear. Indeed, many researchers think that some level of exposure to bacteria and other microbes helps to build a healthy immune system in children.

But, with less-developed immune systems, children are also more vulnerable to certain infections. This means that "squeezing water with chunks of biofilm into their faces ... may result in eye, ear, wound or even gastrointestinal-tract infections," the researchers wrote in the study, which was published in the March issue of the journal Biofilms and Microbiomes.

But future studies are needed to examine the risk of contracting diseases from bath toys, the scientists said.

The researchers added that the plastic materials found in bath toys may play a role in the development of bacteria growth, because these "low-quality polymer" materials often release substantial amounts of organic carbon compounds, which can fuel the growth of microbes. In addition, human bodily fluids and bacteria that shed off our bodies into the water may also contribute to the biofilm growth on bath toys, the researchers said.

Ways to clean bath toys include boiling the toys or removing the water from them after use. But the researchers said that tighter regulations on the types of materials used to make bath toys could also be considered. Better materials that don't leach so many organic compounds could lower microbial growth on the toys, the researchers said.

Original article on Live Science.

Babies aren't so wimpy after all; their kicks in the womb pack about 10 lbs. (4.8 kilograms) of force, according to a new study.

The study, from researchers at  Imperial College London, is the first to quantify babies' kick forces in the womb and the amount of stress that moving around puts on the fetal skeleton, the researchers said.

The researchers used MRI scans of fetuses in their mothers' wombs; the scientists also built computer models to track the movements of the fetuses' joints and calculate the force of the kick and the stresses on the bones. [9 Uncommon Conditions That Pregnancy May Bring]

The study found that the force of the fetal kicks increased during the period between 20 and 30 weeks of gestation. This force went from about 6.5 lbs. (29 Newtons) of force at 20 weeks to 10.5 lbs. (47 Newtons) at 30 weeks. But by 35 weeks, the strength of the fetal kicks had decreased to 3.8 lbs. ( 17 Newtons) of force. This decrease likely occurs because, in late pregnancy, the fetus has less room to move around, the researchers said.

All that kicking plays an important role in fetal development; the stresses on the skeleton likely help with bone and joint formation, the researchers said.

The study was published today (Jan. 24) in the Journal of the Royal Society Interface.

Original article on Live Science.

A foil-wrapped robotic half-baby that looks like it escaped from an unnerving avant-garde art installation is helping researchers to understand how much dirt, pollen, skin cells and bacteria are stirred up — and inhaled — by crawling infants.

When newly mobile babies crawl around their homes or other locations, their mouths and noses are close to the floor. Indoor environments, particularly carpeted areas, can trap a diverse collection of debris, including pollen, skin cells, dirt, fungal spores and bacteria. The new study is the first to analyze indoor debris dispersal and inhalation from a crawling baby's perspective.

To visualize how much of that debris infants might be stirring up with their vigorous movements, scientists built a robotic baby. They took a crawling baby doll and transformed it into a silvery, legless contraption that drags itself forward by paddling its arms, and whose trunk terminated in an array of wires and cables. As the robot scooted over sections of debris-rich carpets — which were taken from actual homes — the study authors collected and analyzed the particle clouds that rose up around it. [Super-Intelligent Machines: 7 Robotic Futures]

"We used state-of-the-art aerosol instrumentation to track the biological particles floating in the air around the infant in real-time, second by second," study co-author Brandon Boor, an assistant professor of civil engineering and environmental and ecological engineering at Purdue University, said in a statement.

In the dust clouds, biological material such as pollen particles, spores and bacteria cells would fluoresce when illuminated by lasers, allowing the researchers to distinguish them from nonbiological airborne materials, Boor said.

Then, a microbiology group at Finland's National Institute for Health and Welfare conducted a DNA analysis of the microbes that the researchers collected on filters.

Close to the ground, concentrations of these floating biological particles are about 20 times denser than they are higher up, the researchers discovered. The amount of material inhaled by infants was therefore significantly higher than the amount an adult would breathe in, by about four times per kilogram of body mass, the scientists reported.

However, this might not be a bad thing for babies, as it could help boost their developing immune systems, according to the study.

The scientists and their nightmarish creation established a novel method for analyzing microbial exposure for mobile babies, but "much remains to be discovered" about the impacts of infants inhaling indoor dust and other particles, Boor said in the statement.

"I hope to continue to work with microbiologists and immunologists to better understand the role of indoor air microbes and allergens on early-childhood health," Boor added.

The findings were published online yesterday (Jan. 11) in the journal Environmental Science and Technology.  

Original article on Live Science.

For an 11-month-old boy in Denver, ingesting marijuana may have triggered a heart problem that ultimately led to his death, according to a recent report of the case.

If the report's hypothesis is true, the case would mark the first time a person has died from a marijuana overdose. But the findings are far from definitive — as a single case, the report cannot prove that marijuana exposure was actually the cause of the infant's death.

"It's very difficult to say that one [thing] caused the other" in this case, said Dr. Jefry Biehler, chairman of pediatrics at Nicklaus Children's Hospital in Miami, who was not involved in the case.

The boy, who was previously healthy, arrived at the emergency room with slowed breathing, and then went into cardiac arrest, according to the report. Shortly before coming to the ER, the boy had appeared sluggish and irritable, and tried to vomit, the report said.

After the child's cardiac arrest, doctors attempted to resuscitate him for an hour, but he ultimately died.

An autopsy revealed that the boy had myocarditis, or inflammation of the heart muscle. Tests also showed the presence of tetrahydrocannabinol, or THC — the active ingredient in marijuana — in the boy's blood and urine samples. [7 Ways Marijuana May Affect the Brain]

Myocarditis can result from a viral or bacterial infection, but the researchers found no solid evidence of an infection in the child. However, the condition can also result from exposure to drugs.

After extensive tests, THC was "the only uncovered risk factor" for the boy's myocarditis, the report said. This suggests "a potential link between the cannabis exposure and myocarditis" in the boy's case, the authors said. The report was published in March in the journal Clinical Practice and Cases in Emergency Medicine.

In children, marijuana has been found to cause symptoms similar to those seen in the boy, including drowsiness, lethargy and nausea. In addition, it's known that marijuana can have some effects on the heart, such as increasing the heart rate.

There have also been other reports of heart complications tied to marijuana use. For example, last year researchers reported a link between marijuana use and an increased risk of a weakened heart muscle. And in 2014, researchers in Germany linked marijuana use to the deaths of two young men, who both died from heart complications. But the new report is the first to link marijuana exposure to death in a child.

Still, it's possible that other factors could have played a role in the boy's myocarditis, Biehler said. Sometimes, when children are found to have myocarditis, "you never figure out why they had it," Biehler said.

In this case, the boy did have one positive test result for bacteria in his blood, meaning it's possible that bacteria contributed to the myocarditis. But because subsequent tests were negative, the researchers said it's more likely that this result was a false positive, due to contamination of the sample with bacteria from somewhere else.

The researchers also don't know exactly when the child ingested marijuana or how much he ingested, although they estimate that the exposure occurred somewhere between two to six days before his death.

All of these factors "make forming definitive conclusions regarding cause and effect difficult in this case report," Biehler said.

Still, "this report certainly deserves consideration and careful review," Biehler told Live Science. "It is obviously concerning that a child may have developed a lethal side effect after exposure to a substance which has become more widely available after legalization," he said. "It remains vitally important that healthcare providers, public health experts, and families remain mindful of the risks that exposure to substances — legal and illegal — represent to children."

The authors of the new report say their findings justify further research into heart problems linked with marijuana exposure. In addition, in states where marijuana is legal "it is important that physicians not only counsel parents on preventing exposure to cannabis, but to also consider cannabis toxicity in unexplained pediatric myocarditis," they concluded.

Original article on Live Science.

Actress Gabrielle Union has had "eight or nine miscarriages," according to an essay published in her new book.

In the book, Union, who is 44, described her struggles with fertility and in vitro fertilization (IVF), according to People magazine.

"For three years, my body has been a prisoner of trying to get pregnant — I've either been about to go into an IVF cycle, in the middle of an IVF cycle, or coming out of an IVF cycle," Union wrote in the book, "We're Going to Need More Wine" (HarperCollins, 2017). "I have had eight or nine miscarriages," she wrote. [6 Myths About Miscarriage]

Up to 20 percent of known pregnancies (in other words, when a woman knows she is pregnant) end in miscarriage, according to the Mayo Clinic. The actual number of miscarriages, however, is probably higher, because many occur very early in pregnancy, before a woman knows she is pregnant, the Mayo Clinic says. But what causes miscarriages? And what factors raise a woman's risk?

The most common cause of miscarriage — which is the spontaneous loss of a fetus before the 20th week of pregnancy — is genetic problems that arise when the fetus is developing, according to the National Library of Medicine. (After the 20th week, the spontaneous loss of a fetus is considered a stillbirth.) These faulty genes are rarely inherited from the mother or the father; rather, the errors occur when the cells of an embryo or a fetus are rapidly dividing. This is especially the case for mothers who have had multiple miscarriages, according to a 2012 study of nearly 500 women that was published in the journal Human Reproduction.

These types of miscarriages have nothing to do with the mother's health or activities; rather, they result from events that occur by chance, according to the Mayo Clinic.

Doctors refer to two or more consecutive miscarriages as "recurrent pregnancy loss," according to UCLA Health. Recurrent pregnancy loss sometimes may be caused by genetic abnormalities in the mother, UCLA Health says, but in more than half of the women with the condition, the cause is unknown. A study from March, published in the journal Mitochondrial DNA Part A, found that recurrent pregnancy loss may be linked to genetic mutations in a woman's mitochondrial DNA. (Mitochondria are the energy powerhouses of cells and have their own DNA separate from the rest of the cell.)

Women with recurrent pregnancy loss have a higher risk of miscarriages, according to the Mayo Clinic.

Certain health conditions can also raise a woman's risk of miscarriage, including uncontrolled diabetes, infections, hormonal problems, uterine or cervical problems, and thyroid disease, according to the Mayo Clinic.

Age is also a risk factor for miscarriage: A 35-year-old woman has about a 20 percent risk of having a miscarriage; a 40-year-old woman has about a 40 percent risk; and a 45-year-old woman has about an 80 percent risk, the Mayo Clinic says.

Smoking, drinking and using drugs also increase a woman's risk of having a miscarriage, according to the National Library of Medicine.

Original article on Live Science.

If you've ever had a concussion, you may have heard that you should take it easy for two weeks or so before easing back into your regular activities. But new research suggests that two weeks may not be sufficient, especially for teenage girls.

The general understanding of how to best manage a concussion largely stems from studies conducted mostly in adult men, many of whom were professional or elite athletes. But women, and in particular, adolescent girls, may need to manage concussions differently, a new study finds.

In fact, girls of middle and high school age can take more than twice as long to recover from a concussion as boys of the same age, according to the study, published today (Oct. 2) in the Journal of the American Osteopathic Association.

In the study, researchers looked at the medical records of more than 200 adolescent athletes, ages 11 to 18, who had each experienced one concussion. Roughly half of the athletes were male and half were female. The researchers looked at how long each athlete's symptoms lasted after the concussion. [10 Things You Didn't Know About the Brain]

The median duration of symptoms was 11 days for boys and 28 days for girls, the researchers found. This means that the recommendation that athletes stay out of action for about two weeks after the injury would cover boys, while girls wouldn't have reached even the halfway point in their recovery.

The findings "confirm what many in sports medicine have believed for some time," lead study author Dr. John Neidecker, a sports-related concussion specialist at Orthopaedic Specialists of North Carolina, said in a statement.

Part of the difference between boys' and girls' recovery times might be explained by biological differences between their brains that aren't particularly well-understood, Neidecker told Live Science.

Underlying medical conditions could also play a role. Conditions such as depression, anxiety or migraines could cause concussion-like difficulties with focus, attention, balance or pain, and a concussion should aggravate or exacerbate these symptoms.

"Most of these conditions are more [common] in females than males," Neidecker said. The longer duration of symptoms observed in adolescent girls after concussions could therefore be the result of an "aggravated pre-existing condition," he said.

In April, top concussion researchers from around the world released a consensus statement from the 5th International Conference on Concussion in Sport on how to study, prevent, manage and treat concussions. The statement noted that earlier research showed that concussions can exacerbate other conditions, including depression, anxiety, headaches and stress.

Neidecker agreed that stress can also play a role. "This is a stressful injury," he said. "It's stressful being an adolescent, and stress in itself can bring in concussion symptoms — irritability, difficulty sleeping [and] difficulty concentrating. It's hard to tell what's from stress and what's from the injury."

To better treat concussions in adolescent girls, it's crucial for doctors to find out what pre-existing conditions patients may have, Neidecker said. Knowing if a patient also has depression or migraines, for example, can help a doctor recommend more-appropriate treatments sooner, which can help bring the gap in recovery time between the genders down, Neidecker said.

The problem is that many adolescents may not know if they have migraines, for example, and instead assume that their headaches are normal, Neidecker said. In these cases, doctors need to get creative to tease the information out, he said.

The researchers noted that the study had limitations. For example, the patients included in the study self-reported their symptoms, which may have introduced inaccuracies. In addition, the research was conducted at a medical practice in New Jersey that focused on sports-related concussions, and this specialization means that the doctors may have been treating more-severe cases than those that occur in the general population, the researchers said.

Originally published on Live Science.

A 47-year-old British man who was being tested for lung cancer received some good, but unexpected, news: Instead of signs of cancer in the man's lungs, doctors found a tiny Playmobil plastic traffic cone lodged in his airways, according to a new report of the man's case.

The toy turned out to be a part of a set the individual had received — and shortly after, accidentally inhaled — 40 years earlier, according to the case, published Sept. 22 in the journal BMJ Case Reports. Back then, the play set had been given to him for his seventh birthday.

Upon learning of his odd diagnosis, the man said that he did recall putting pieces from the play set in his mouth when he was little. But amazingly, the plastic cone had remained undetected in his lungs for four decades, until it caused a "traffic jam" in his airways and triggered a nagging cough. [27 Oddest Medical Cases]

In the man's case, the long-lost toy was discovered when he sought help from his doctor for a bout of pneumonia. He was an ex-smoker and had smoked about a pack a day for 30 years, according to the case report.

The man's pneumonia was treated with antibiotics, but he continued to have a phlegmy cough, so he was sent to a lung specialist. The lung specialist took an X-ray of the man's chest and saw what he thought were signs of a possible cancerous growth, according to the report.

To investigate further, doctors performed a bronchoscopy, a procedure in which a flexible tube is inserted into the lungs to figure out the cause of blocked airways. 

But instead of detecting a tumor, the doctors discovered a tiny plastic object that was partially blocking one of the main airways leading to a section of the man's right lung, said lead author Dr. Nicholas Denny. At the time of the case, Denny was getting his medical training at Wythenshawe Hospital in Manchester, England.

Denny said doctors think that the boy put the plastic traffic cone in his mouth and then accidentally inhaled it, as opposed to swallowing the toy.

After doctors successfully removed the object, it was identified as a plastic Playmobil traffic cone, according to the report of the case.

Lost and found

It may seem unusual that a plastic object — which was, after all, stuck in the man's airways — did not cause symptoms sooner, and so was overlooked for four decades. [11 Weird Things People Have Swallowed]

It's almost certain that the man would have had symptoms as a child, such as coughing or chest pain, immediately after he inhaled the toy, Denny told Live Science, but these symptoms might have been blamed on a short-term illness. And because the toy traffic cone is hollow with holes on either end, it may have allowed for airflow in the passageways of the lungs rather than interfering with it, Denny said.

As the boy got older, the airway may have adapted around the plastic traffic cone, by absorbing the toy into the mucosal lining so that the airway developed around it, Denny said. Although the toy may have caused some obstruction in the airway, it may not have caused any symptoms, he explained.

The man's smoking habits may have also contributed to the delay in detection: Smoking may have suppressed his immune function in the airways, making it more difficult to clear away secretions, such as mucus, and making him more vulnerable to infections, Denny said.

These secretions might have been cleared from a normal airway, Denny said, but in this man's case, the combination of being a long-term smoker along with the partial obstruction from the lodged toy prevented such secretions from being cleared. This buildup of secretions ultimately led to the man developing pneumonia. Two months later, lung specialists finally discovered that the man's symptoms, including the lingering cough, were connected to the inhaled toy.

"On a positive note, his symptoms improved markedly, and he finally found his long-lost Playmobil traffic cone in the very last place he would look [for it]," the case report authors wrote. 

Originally published on Live Science.

A Colorado toddler narrowly avoided surgery after she swallowed 28 buckyball magnets, according to news reports.

An X-ray revealed that the small but strong magnets had linked up to form a circle in the 2-year-old's gut, and two of the magnets were pinching a bit of her bowel, Fox 31 Denver reported on Sept. 24.

The magnets "were pinching [her] bowel and causing the early formation of a hole within the bowel by the time we got in there," Dr. Robert Kramer, director of endoscopy at Children's Hospital Colorado, told Fox 31. Kramer removed the magnets using a special type of endoscopy, which involves inserting a long tube down through a person's mouth, into the gut. If the endoscopy hadn't worked, doctors would have needed to operate. [11 Weird Things People Have Swallowed]

Kramer told Fox 31 that the girl was lucky — in some cases, the magnets can cause holes, and doctors need to remove part of the intestine.

Buckyballs are BB-sized, superstrong magnets made of the rare earth metal neodymium. In 2013, the U.S. Consumer Product Safety Commission (CPSC) issued a recall on the magnets and also announced that it was illegal to sell them. The magnets can stick to one another through the walls of the stomach or the intestines, causing serious injuries, including holes, intestinal blockages, blood poisoning and death, according to the CPSC.

But in December 2016, an appeals court overturned the CPSC's decision, and retailers are now allowed to sell the magnets once again, according to Fox News.

"We are seeing these cases [of kids swallowing the magnets] come back again," Kramer said.

In the toddler's case, the girl's father had the magnets on his desk. He had stepped away to use the bathroom, and when he came back, he found the girl holding them. That worried him, as his daughter liked to put toys in her mouth, Fox 31 reported. This prompted the parents to take the girl for an X-ray, even though she hadn't shown any symptoms.  

A medical emergency

When someone swallows two or more magnets, it's an emergency, said Dr. Shifra Koyfman, a pediatric gastroenterologist at Nicklaus Children's Hospital in Miami. Koyfman was not involved in the Colorado toddler's case.

That's because the magnetic force between the objects pulls them together, and when that happens in the gut, it can pull together two parts of the digestive tract that shouldn't normally touch, and create holes, Koyfman told Live Science. For example, in one case that Koyfman worked on, X-rays showed magnets in the patient's stomach and large intestine, where they had drawn the two organs together, and surgery was needed. [9 Weird Ways Kids Can Get Hurt]

Gastroenterologists can usually remove magnets using an endoscope, if the magnets are in the stomach or the upper part of the small intestine, Koyfman said. An endoscope is a long tube with a camera and small tools, such as forceps, that can be inserted into the stomach and small intestine through a person's mouth. If the magnets are farther down in the small intestine or in the large intestine, surgery may be required, she said.

Buckyballs are "pretty dangerous," Koyfman added, because they're powerful magnets, as well as very small and easy for kids to swallow.

Ingesting magnets can lead to symptoms including belly pain and vomiting, Koyfman said, and if magnets cause a hole, a person may have blood in his or her vomit.

Koyfman said she tells parents to keep anything they don't want their kids to swallow locked up and put away. And "if kids swallow [magnets], bring them to the emergency room," she said. 

Originally published on Live Science.

Children who watch movies that include gun violence may be more likely to use guns themselves, a new study finds.

In the study, kids who watched a movie with gun violence later played with a gun for longer and pulled the trigger more times than kids who watched a movie without gun violence, according to the study, published today (Sept. 25) in the journal JAMA Pediatrics. The study used a real, but unloaded gun, and the children's parents gave consent.

The study is unlike any previous research conducted on the subject, said senior study author Brad Bushman, a professor of communication and psychology at the Ohio State University. But the findings were not surprising, he said. [9 Weird Ways Kids Can Get Hurt]

"Kids think movie characters are cool, and kids want to imitate movie characters," Bushman told Live Science. Indeed, previous research showed that kids who see movie characters smoking cigarettes are more likely to smoke themselves, and kids who see movie characters drinking alcohol are more likely to drink themselves, Bushman said. "It would be more surprising if [kids] imitated movie characters who smoked and drank but didn't imitate movie characters who did other things," he said.

Still, the study is likely to drum up controversy; indeed, it touches two "third rails" of academic medicine: media violence and guns, two editors of JAMA Pediatrics wrote in an editorial published alongside the study.

"We are aware that critics will seek flaws in the science and take issue with the conclusions," Dr. Dimitri Christakis, associate editor of the journal, and Dr. Frederick Rivara, editor of the journal, wrote in the editorial. However, they stressed the rigor of the science and data analysis.

Movie and play time

The study involved 52 pairs of children ages 8 to 12. The pairs were randomly assigned to watch a 20-minute version of a PG-rated movie either containing gun violence or not containing gun violence. Both movies contained action sequences. Following the movie, the pairs of children were taken to a separate room that had a cabinet filled with toys and games, including Legos, Nerf guns and checkers.

The cabinet also contained a real handgun. The gun was unloaded and modified so that it could not fire, but it was wired to count how many times the trigger was pulled. (The children's parents were informed that the experiment would involve this gun, and they gave their consent.) The gun was hidden, but the children in the study could find it if they looked, Bushman said.

The researchers told the kids that they could play with anything in the room for 20 minutes, and then left the pairs of children unattended. A researcher sat just outside the room, in case the kids had any questions. In addition, parents and other researchers watched the kids in the playroom on live video. [Top 5 Benefits of Play]

In 43 of the 52 pairs of kids in the study, one or both of the children found the gun in the playroom; of these, 22 of the pairs handled the gun, and 14 either gave the gun to the research assistant sitting outside or told the research assistant that they had found a gun.

On average, pairs of children who watched the movies with gun violence pulled the gun's trigger more than those who watched the movies without gun violence: The median number of trigger pulls for pairs who saw the movie with guns was three, compared with zero for pairs who watched the movie without guns. In addition, those who watched the movie with guns held the gun for a median of 53 seconds, compared with 11 seconds for the kids who watched the movie without guns.

Boys tended to pull the trigger more times than girls did, the researchers found. However, there were no differences between the sexes in how long the children held the gun.

The lab vs. the real world

The researchers noted that the study had several limitations. For example, only one real gun was used in the study, but two Nerf guns were available. This may have inadvertently encouraged the kids to play with the Nerf guns instead, the researchers wrote.

In addition, conducting future research in a more natural setting, such as a real home, would make the findings more generalizable, the study said.

But Bushman noted that "lots of other study findings on media violence apply outside of the lab, so it's hard to imagine that it would not apply outside [the lab] for this study but would for every other type of study."

"Skeptics will note that the non-real-world nature of the study limits its implications," Christakis and Rivara wrote in the editorial. But they also argued that the findings must be put in context.

"The children were not in their homes, but might the experimental situation be akin to being at a friend's home, a not-uncommon place where fatal unintentional shootings of children occur?" the editorial authors wrote. "If anything, the nature of the experiment — being in an unfamiliar setting — might induce them to report the gun (it wasn't theirs after all) or to feel less comfortable with it." [5 Milestones in Gun Control History]

Advice for parents

Bushman advised parents to be careful about what their children see in the media.

"Acts of gun violence in PG-13 movies have more than tripled since 1985," he said. In the study, the movies selected were rated PG, so it's possible that watching more-graphic representations of gun violence could have a greater effect on kids' likelihood to use a gun, he said.

Movies that contain drinking and smoking contain warnings, Bushman said, so why not have a warning for movie characters who use guns?

In addition, Bushman stressed the importance of locking up guns. "Sixty percent of gun owners don't" lock up their guns, and children may discover the weapons because of that, he said.

Originally published on Live Science.

Have you ever struggled to open a stubborn package? If so, that may be a good thing…if your baby is watching.

A new study finds that babies as young as 13 months old can learn perseverance by watching you muddle through failure and repeatedly attempt to reach a goal.

In the study, researchers presented babies with a challenge to activate a musical toy box. Babies who had just witnessed an adult struggle with a different kind of task a few seconds earlier, such as removing a key chain from a carabiner, tried harder to overcome their own little challenge, compared with babies who didn't witness such a struggle. [11 Facts Every Parent Should Know About Their Baby's Brain]

The findings, published today (Sept. 21) in the journal Science, suggest there is "potential value in letting children 'see you sweat,'" the researchers wrote in their paper. "Showing children that hard work works might encourage them to work hard too."

Previous studies have shown that school-age children who persevere through modestly complicated tasks tend to be more successful academically later in life. However, scientists have not been able to determine how and when children develop such true grit.

Most studies in this area have focused on children in grade school and middle school. Researchers at Stanford University, for example, found that seventh-graders who thought that intelligence was malleable and that effort determines achievement outperformed their peers who thought intelligence was fixed. The study was conducted over a two-year period through middle school.

In the new study, researchers at the Massachusetts Institute of Technology (MIT) wanted to see if babies might be inspired to persevere by witnessing a struggle that resulted in success. To do so, they recruited more than 260 babies (and their guardians).

The babies, ages 13 to 18 months, were placed in three testing categories: A third of them watched an adult struggle and succeed with a task; a third watched adults succeed in a task easily; and a third were in a control group, not witnessing adults perform any kind of task.

The task was either opening a container or removing a key chain from a carabiner. In the first group, the adult would pretend to struggle for 30 seconds with the task and then succeed, all the while making eye contact with the baby and saying things such as, "Hmm, I wonder how I can get my toy out of here?"

In the second group, the adult completed the task without struggling in 10 seconds, and then repeated this task twice more over the next 20 seconds.

In all the groups, an adult would give the baby a trick music box with a big button that was inert and a hidden button that played music. The adult would activate the musical sound, hand the toy to the baby and leave the room. [Top 5 Benefits of Play]

Although no babies found the hidden button, those who had witnessed an adult struggle pushed the inert button significantly more often and probed the toy longer before giving up, compared with the babies in the other groups. In fact, there were no significant differences in the amount of time both other groups examined the toy.

The researchers hope that "the study reassures parents that they don't have to make everything look like it comes easily," said lead study author Julia Leonard, a graduate student at MIT.

Leonard added that more research is needed to gauge the effects of watching adults struggle through tasks on babies' perseverance. "We have a lot of respect for parents and wouldn't presume to use a single laboratory study as a basis for parenting advice," Leonard told Live Science.

"However, we hope the study might interest parents, and we'd be interested in knowing from parents whether simply showing children a couple of examples of struggling before succeeding seems to help their children persist more on tasks where the parent is confident that the child might succeed with effort," she said.

And what about watching parents struggle through a task unsuccessfully? The researchers said they hope to investigate this in future studies. If an adult fails to achieve a goal, the baby might conclude that the task is beyond its ability, the researchers said.

Follow Christopher Wanjek @wanjek for daily tweets on health and science with a humorous edge. Wanjek is the author of "Food at Work" and "Bad Medicine." His column, Bad Medicine, appears regularly on Live Science.

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

Teens aren't what they used to be.

The teen pregnancy rate has reached an all-time low. Fewer teens are drinking alcohol, having sex or working part-time jobs. And as I found in a newly released analysis of seven large surveys, teens are also now less likely to drive, date or go out without their parents than their counterparts 10 or 20 years ago.

Some have tried to explain certain aspects of these trends. Today's teens are more virtuous and responsible, sociologist David Finkelhor has argued. No, says journalist Jess Williams, they're just more boring. Others have suggested that teens aren't working because they are simply lazy.

However, none of these researchers and writers has been able to tie everything together. Not drinking or having sex might be considered "virtuous," but not driving or working is unrelated to virtue – and might actually be seen as less responsible. A lower teen pregnancy rate isn't "boring" or "lazy"; it's fantastic.

These trends continued even as the economy improved after 2011, suggesting the Great Recession isn't the primary cause. Nor is more schoolwork: The average teen today spends less time on homework than his counterparts did in the 1990s, with time spent on extracurricular activities staying about the same.

To figure out what's really going on, it's worth taking a broader look at today's teens – a generation of kids I call "iGen" – and the environment they're living in.

A different culture, a slower path

Working, driving, drinking alcohol, having sex and dating have one thing in common: They are all activities adults do. This generation of teens, then, is delaying the responsibilities and pleasures of adulthood.

Adolescence – once the beginning of adulthood – now seems to be an extension of childhood. It's not that teens are more virtuous or lazier. They could simply be taking longer to grow up.

Looking at these trends through the lens of "life history theory" might be useful. According to this model, whether development is "slow" (with teens taking longer to get to adulthood) or "fast" (getting to adulthood sooner) depends on cultural context.

A "slow life strategy" is more common in times and places where families have fewer children and spend more time cultivating each child's growth and development. This is a good description of our current culture in the U.S., when the average family has two children, kids can start playing organized sports as preschoolers and preparing for college can begin as early as elementary school. This isn't a class phenomenon; I found in my analysis that the trend of growing up more slowly doesn't discriminate between teens from less advantaged backgrounds and those from wealthier families.

A "fast-life strategy," on the other hand, was the more common parenting approach in the mid-20th century, when fewer labor-saving devices were available and the average woman had four children. As a result, kids needed to fend for themselves sooner. When my uncle told me he went skinny-dipping with his friends when he was eight, I wondered why his parents gave him permission.

Then I remembered: His parents had six other children (with one more to come), ran a farm and it was 1947. The parents needed to focus on day-to-day survival, not making sure their kids had violin lessons by age five.

Is growing up slowly good or bad?

Life history theory explicitly notes that slow and fast life strategies are adaptations to a particular environment, so each isn't inherently "good" or "bad." Likewise, viewing the trends in teen behavior as "good" or "bad" (or as teens being more "mature" or "immature," or more "responsible" or "lazy") misses the big picture: slower development toward adulthood. And it's not just teens – children are less likely to walk to and from school and are more closely supervised, while young adults are taking longer to settle into careers, marry and have children.

"Adulting" – which refers to young adults performing adult responsibilities as if this were remarkable – has now entered the lexicon. The entire developmental path from infancy to full adulthood has slowed.

But like any adaptation, the slow life strategy has trade-offs. It’s definitely a good thing that fewer teens are having sex and drinking alcohol. But what about when they go to college and suddenly enter an environment where sex and alcohol are rampant? For example, although fewer 18-year-olds now binge-drink, 21- to 22-year-olds still binge-drink at roughly the same rate as they have since the 1980s. One study found that teens who rapidly increased their binge-drinking were more at risk of alcohol dependence and adjustment issues than those who learned to drink over a longer period of time. Delaying exposure to alcohol, then, could make young adults less prepared to deal with drinking in college.

The same might be true of teens who don’t work, drive or go out much in high school. Yes, they're probably less likely to get into an accident, but they may also arrive at college or the workplace less prepared to make decisions on their own.

College administrators describe students who can't do anything without calling their parents. Employers worry that more young employees lack the ability to work independently. Although I found in my analyses that iGen evinces a stronger work ethic than millennials, they'll probably also require more guidance as they transition into adulthood.

Even with the downsides in mind, it's likely beneficial that teens are spending more time developing socially and emotionally before they date, have sex, drink alcohol and work for pay. The key is to make sure that teens eventually get the opportunity to develop the skills they will need as adults: independence, along with social and decision-making skills.

For parents, this might mean making a concerted effort to push your teenagers out of the house more. Otherwise, they might just want to live with you forever.

Jean Twenge, Professor of Psychology, San Diego State University

This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

American men are having children at increasingly older ages, according to a new study.

Over roughly the past four decades, the average age of U.S. fathers at the time of their child's birth increased by 3.5 years, from 27.4 years in 1972 to 30.9 years in 2015, according to the study.

What's more, the percentage of fathers who were older than 40 when they had children doubled during the study period, from 4.1 percent in 1972 to 8.9 percent in 2015.

The rising age of dads in the United States could have public health implications, the researchers said. It's estimated that a man acquires about two new mutations in the DNA of his sperm each year, study co-author Dr. Michael Eisenberg, an assistant professor of urology at Stanford University School of Medicine, said in a statement.

This means that, in theory, children of older dads could be at higher risk of certain genetic conditions. Indeed, previous studies have found "associations between older fatherhood and higher rates of autism, schizophrenia, chromosomal abnormalities, some pediatric cancers and certain rare genetic conditions" in children, Eisenberg said.

Still, there could also be benefits to this trend — one study found that fathers ages 35 to 44 were more likely to live with their children, and thus be more involved in child rearing, than fathers ages 15 to 24, the researchers said. [Trying to Conceive: 12 Tips for Men]

Numerous studies have shown that the age at which women first have children has been on the rise since the 1970s. But far fewer studies have looked at changes in the age of new fathers in recent decades.

The new study analyzed data from more than 168 million U.S. births over a four-decade period. The researchers used birth certificates (available through a government database) to gather information on the age, race/ethnicity and education level of fathers, for each year of the study.

During the study period, the average age of fathers at the time of their child's birth increased for all races/ethnicities and education levels.

Overall, Asian-American dads tended to be older. In 2015, men of Japanese and Chinese decent were, on average, 35 to 36 years old at the time of their child's birth. African-American and Hispanic dads tended to be younger, around 30 years old, at the time of their child's birth.

Men with more education also tended to be older when they had children; in 2015, the average age of fathers with a college degree was 33 years old.

A similar trend of increasing paternal age has been seen in other countries, including England and Germany.

Factors such as the increased availability of contraception, as well as the increased entry of women into the workforce, may have played a role in the rising age of both men and women at the time of their children's birth, the researchers said.

The rising age of new parents could have an effect on family size, since older people have fewer years left for childbearing than younger people do, the researchers said.

The researchers called for more studies on the health and social implications of older fathers.

The study is published today (Aug. 30) in the journal Human Reproduction.

Original article on Live Science.

Drug overdose deaths among U.S. teens edged upward in 2015, after declining for several years prior, according a new report.

The report, from the Centers for Disease Control and Prevention (CDC), looked at drug overdose deaths among Americans ages 15 to 19 over a 16-year period, from 1999 to 2015.

The report showed that from 1999 to the mid-2000s drug overdose deaths in this age group more than doubled, from 1.6 deaths per 100,000 people in 1999 to 4.2 deaths per 100,000 people in 2007. This increase coincided with a rise in drug overdose deaths among the U.S. population as a whole, an increase that's been partly attributed to the opioid epidemic.

However, after 2007, drug overdose deaths among teens declined, reaching 3.1 deaths per 100,000 people in 2014, the report said. (This drop was driven by a decrease in drug overdose deaths among males in this age group.)

But in 2015, the most recent year for which data is available, drug overdose deaths among teens increased again, to 3.7 deaths per 100,000 people, which is a 19 percent increase compared to 2014, the report said. In total, there were 772 drug overdose deaths in this age group in 2015. [America's Opioid-Use Epidemic: 5 Startling Facts]

This recent rise "certainly is a red flag," said Dr. Bradley Stein, a child and adolescent psychiatrist and senior physician policy researcher at the RAND Corporation, who was not involved in the report. However, Stein noted, because the overall number of drug overdose deaths among teens in this age group is relatively small, it's possible that the recent rise is just statistical "noise" rather than a true increase. In other words, more data will be needed to determine if this marks a new upward trend.

Still, "any uptick at all [in drug overdose deaths] is certainly something that has to get our attention," Stein said.

The majority of overdose deaths in this age group, 80 percent, were unintentional. However, the rate of suicides resulting from overdose was higher among females (22 percent) than males (13.5 percent), the study found.

The report analyzed the types of drugs involved in teen overdose deaths, finding that opioids had the highest death rate, followed by benzodiazepines (which are also known as "tranquilizers" and include drugs such as Valium and Xanax).

Stein noted that while people often focus on opioids as the biggest culprit in drug overdose deaths, it's often a combination of drugs that leads to overdose, and the mixture of opioids with benzodiazepines can be particularly deadly.

The study also found that there has been a spike in teen overdose deaths involving heroin and synthetic opioids (such as fentanyl) in recent years, while there has been a decrease in deaths involving semisynthetic opioids, which include prescription painkillers such as hydrocodone and oxycodone. This mirrors a trend seen in adults and suggests that while efforts to reduce prescribing of opioid painkillers may be working, they are "not a silver bullet" for solving the opioid crisis, Stein said.

Stein said it's unclear why teen drug overdose deaths decreased from 2007 to 2014 while overdose deaths increased in other age groups during this time. But Stein speculated that efforts to prevent opioid use or educate people about the risks of these drugs might have a bigger impact in teens and might prevent them from starting in the first place. More research is needed to understand which interventions work best for which demographic groups, he said.

Still, even with prevention efforts, teens may become addicted to opioids, and there is still a need to push for better opioid addiction treatments for this age group, Stein said.

The report is published today (Aug. 16) by the CDC's National Center for Health Statistics.

Original article on Live Science.

Can Beyoncé ever catch a break?

The singer and mom to 2-month-old twins Sir and Rumi Carter posted photos to her Instagram account last weekend that showed her and her husband, rapper Jay-Z, sipping on what looks like wine or liquor.

The photos prompted cries of outrage that Beyoncé might be drinking alcohol while breast-feeding. (It's not clear if the singer is currently breast-feeding the twins; she told People magazine after giving birth to her first child, Blue Ivy, that she breast-fed for 10 weeks.) [Beyoncé Expecting 2: Here Are 5 Fun Facts About Twins]

But is drinking alcohol while breast-feeding dangerous for the baby?

It's true that alcohol can be found in a woman's breast milk after drinking, according to theAmerican Academy of Pediatrics (AAP). Because of this, the AAP advises women to avoid habitual alcohol consumption when breast-feeding. 

But an occasional drink is OK, especially if a woman has the drink after she's just nursed or pumped, the AAP says. Women should wait at least 2 hours per alcoholic drink before breast-feeding or pumping milk; this way, the body has as much time as possible to rid itself of the alcohol, the AAP says. One drink is equivalent to a 12-ounce (350 milliliters) beer, a 4-ounce (120 mL) glass of wine or 1 ounce (30 mL) of hard liquor.

La Leche League International (LLLI), a nonprofit breast-feeding advocacy group, agrees that an occasional drink is OK for a breast-feeding mom. "When the breast-feeding mother drinks occasionally or limits her consumption to one drink or less per day, the amount of alcohol her baby receives has not been proven to be harmful," LLLI says.

The amount of alcohol found in breast milk peaks about 30 to 60 minutes after the mother drinks alcohol, and about 60 to 90 minutes after she drinks if the woman has a drink with food, LLLI says. For a woman who weighs 120 lbs. (54 kilograms), it would take from 2 to 3 hours for her body to eliminate the alcohol completely from a serving of beer or wine, the group says, and a high-alcohol drink could take up to 13 hours to clear from the body.

The backlash aimed at Beyoncé isn't unique to celebrities: More than 60 percent of mothers of young children say that they've been criticized for their parenting decisions, according to a survey from the University of Michigan from June. 

Originally published on Live Science.

A baby boy in India was born with his own "twin" inside his abdomen — an extremely rare condition called "fetus in fetu." But what causes this to happen?

Doctors first noticed something was wrong when they spotted a mass inside the fetus during a routine ultrasound of the pregnant mother, according to Metro, a news outlet based in the United Kingdom. After the baby was born, doctors performed another scan, and found a partial fetus behind the baby's stomach. The partial fetus had arms, legs and a brain, but no skull, Metro reported.

Related: An X-ray showing 100 bubble tea pearls in a teen's abdomen has doctors very confused

The term "fetus in fetu," which literally means "fetus within fetus," is usually defined as a condition in which a developmentally abnormal fetus is found inside the body of its otherwise healthy twin.

It is not exactly clear what causes fetus in fetu. But scientists think the condition is likely a rare form of "parasitic twins," according to Arizona State University. Parasitic twins happen when, during an identical-twin pregnancy, one of the fetuses is absorbed by the other early in pregnancy. The tissues of the parasitic twin are dependent upon the body systems of the "host" twin to survive, according to a 2010 review paper on parasitic twins.

However, some researchers think that fetus in fetu is actually a kind of teratoma — a type of tumor that can contain all three of the major cell types that are found in an early-stage human embryo.

Fetus in fetu is very rare, occurring in only about 1 in 500,000 births, according to a 2010 report on the phenomenon.

In the case of the Indian baby, doctors performed surgery to remove the 2.8-inch-long (7 centimeters) parasitic twin, which weighed about 5.3 ounces (150 grams), Metro said. Both the baby and the mother are reportedly doing well.

Original article on Live Science.

A child in South Africa who was born with HIV has been virtually free of the virus for nearly nine years now and didn't take anti-HIV drugs for most of that time, according to a new report of the case.

The child was treated with HIV medications early in life, but has not received anti-HIV drugs for eight and a half years, according to the researchers, who reported the case today (July 24) at an international AIDS conference in Paris.

The researchers hope that by studying this child, they may gain a better understanding of how a person's body can, in some cases, control HIV without the use of daily drugs. Such further research may potentially lead to new, long-acting treatments for the disease. [27 Devastating Infectious Diseases]

"Further study is needed to learn how to induce long-term HIV remission in infected babies," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), said in a statement. "However, this new case strengthens our hope that by treating HIV-infected children for a brief period beginning in infancy, we may be able to spare them the burden of life-long therapy" and the health consequences of long-term HIV infection, Fauci said.

The South African child was diagnosed with HIV in 2007 at 32 days old. The child was enrolled in a study, funded by NIAID, that aimed to test the effects of early HIV treatment. Children in the study were randomly assigned to receive antiretroviral therapy (ART) drugs either immediately after their HIV diagnosis, or only once they showed symptoms of the disease.

The child in the new report received ART drugs immediately after diagnosis and continued receiving them for 40 weeks. After the treatment stopped, the researchers could no longer detect HIV in the child's blood; and follow-up tests showed that the child remained healthy and HIV-free in the years following the treatment.

When the child was nine and a half years old, the researchers conducted rigorous testing to determine if HIV was present anywhere in the child's body. They used very sensitive test, and found that a tiny proportion of the child's immune cells contained the virus, but the virus was dormant. The researchers otherwise found no evidence of HIV — standard tests could not detect the virus and the child had no symptoms.

This isn't the first time that early HIV treatment has led to apparent remission in a child. In 2013, researchers reported the case of a baby born with HIV in Mississippi who was treated with anti-HIV drugs just 30 hours after birth. In that case, the baby remained apparently HIV-free for more than two years without drug treatment, until the virus reappeared in her blood. In 2015, researchers in France reported the case of an HIV-positive child who began treatment at 3 months of age, but later stopped treatment and remained HIV-free more than 11 years later.

It's not exactly clear why some children may be able to live so long without needing ongoing HIV treatment. It's thought that early treatment with anti-HIV drugs may prevent the virus from establishing reservoirs, or "hiding places," in the body, which allow the virus to reemerge when treatment stops.

It's also likely that the South African child has other, innate factors that contributed to that person's HIV remission, the researchers said. Among the 143 infants who received the same treatment — 40 weeks of ART immediately after diagnosis — the average length of remission was about 30 weeks, according to the Washington Post. Some children in the study were in remission for more than two years, but no others went as long as the 8.5 years that was seen in the current case.

"By further studying the child, we may expand our understanding of how the immune system controls HIV replication," said study co-author Caroline Tiemessen, head of cell biology at South Africa's National Institute for Communicable Diseases (NICD) in Johannesburg.

The U.S. National Institutes of Health is currently conducting a trial to test whether giving ART to HIV-infected babies within 48 hours of birth leads to long-term control of the virus after treatment is stopped.

Original article on Live Science.