Miscarriage: Signs, symptoms & causes

Pregnancy should be an exciting time, but for many women the fear of having a miscarriage can overshadow this.

“There are many different kinds of miscarriage, however this overarching term is categorized as the spontaneous loss of a pregnancy before the 20th week,” says Dr Evangelia Elenis, chief physician in Obstetrics and Gynecology and chief medical advisor at AI-led fertility app Tilly.

“Whatever stage a miscarriage is at — whether it's five weeks or 20 — it's still a pregnancy loss and if that pregnancy has been meticulously planned and anxiously awaited, it can be all the more devastating,” adds midwife Kate Taylor, from The PEP Midwives. “It is grief at the end of the day and it’s very sad for all involved.” 

Miscarriages are relatively common —  most happen during the first 12 weeks of pregnancy, known as the first trimester and about 10-20% of pregnancies end in miscarriage (around 1 million a year in the US). But that doesn’t mean it’s any less upsetting, especially if it happens multiple times. And because talking about miscarriage and grief can make people uncomfortable, it’s often a taboo subject.

“No matter how common they are, miscarriages are sad,” says Taylor. “Afterwards, women can find it traumatizing to be around people who are pregnant, as well as adjusting to having a bump that no longer has a baby in it.”

The good news is that, according to the American Pregnancy Association, most women (about 85%) who miscarry will go on to have a healthy pregnancy later. In this article we talk to the experts to find out more about the signs, symptoms and causes of miscarriage.

Types of miscarriage

There are many types of miscarriage, but the following are the most common:

Chemical pregnancy

“A chemical pregnancy is an early pregnancy loss that occurs within two to seven days after implantation,” says Dr Elenis. “Because chemical pregnancies occur so early on, ultrasounds aren’t able to detect the fetus, but pregnancy tests can still come up positive as the ‘pregnancy hormone’ human chorionic gonadotropin (hCG) is present in the body. It’s very common for people to not know that they’re pregnant at this stage, and it’s most often noticed by those who are actively trying to conceive. Typically, chemical pregnancies occur because there is a problem with the embryo’s DNA that stops it from developing, but it’s often likely that the next embryo will develop without issue, if wider fertility complications are not at play.”

Dr Evangelia Elenis, MD, PhD

Dr Elenis is a chief physician in Obstetrics and Gynecology, and a subspecialist in Reproductive Medicine. She is a PhD and affiliated researcher at Uppsala University with postdoctoral studies at Harvard Medical School.

Early miscarriage

“Early miscarriage is the most common type of miscarriage, and occurs in 10-20% of all pregnancies, typically before 12 weeks,” says Dr Elenis. “Because it’s so common, many people typically wait until after the first trimester to tell friends and family about their pregnancy. Early miscarriage typically occurs because the embryo does not develop correctly, often due to an abnormal number of chromosomes. Not all eggs and sperm contain a normal number of chromosomes and often fertilization or implantation doesn’t happen at all (as in, you don’t become pregnant), but if you do it will end in an early miscarriage.”

Late miscarriage

Late miscarriage typically occurs from weeks 12-24, but these are are significantly less common, occuring in about 1-2% of pregnancies. “These miscarriages can also be caused by chromosomal and genetic factors, but they tend to involve wider factors such as infections like bacterial vaginosis (BV), anatomical issues like the shape of the womb, placental problems, long term health issues like severe high blood pressure, or invasive prenatal tests (which have a very small risk of causing miscarriage),” says Dr Elenis.

Recurrent miscarriage

Recurrent miscarriage, or recurrent pregnancy loss, is when a person has more than two or three consecutive miscarriages (the number varies by country). “The diagnosis of recurrent miscarriages is uncommon and given to a very small number of women, around 1%,” says Dr Elenis. “When you have several miscarriages in a row, the chance that the reason is abnormal chromosomes decreases, and the risk for maternal underlying health conditions increases. Factors that can play a role involve issues with the thyroid, blood clots, genetics and the immune system, and it’s very important to get to the root of the issue with a medical expert in order to find a solution.”

“Other types of miscarriage include stillbirth, when a baby is born dead after 24 completed weeks of pregnancy, and a ‘complete’ miscarriage, when all the pregnancy tissues come away without needing medical assistance,” says Dr. Hana Patel, who specializes in women’s health. “An ‘incomplete’ miscarriage is when not all the pregnancy tissue comes away and medical assistance is required.”

Who is at risk of miscarriage?

According to Patel, there are certain factors that put a woman more at risk of miscarriage, including being overweight, having particular chronic health conditions, previous history of miscarriage and other social risk factors such as alcohol intake and recreational drugs.

Other risk factors include:

• Older mothers – With age, the average share of eggs with a normal number of chromosomes inevitably decreases, which not only makes it more difficult to become pregnant, but also increases the risk of miscarriage. 
• Smokers – Eggs and sperm are cells, and their quality is harmed by everything that causes what’s known as ‘oxidative stress’ — an imbalance between free radicals and antioxidants in the body. As such, smoking causes more abnormal eggs and sperm, which can put smokers at a higher risk of miscarriage. 

More widely, the following health conditions put mothers at higher risk of miscarriages: 

• Thyroid issues – Untreated thyroid conditions can cause problems for mothers and their baby during pregnancy and after birth, and have also been associated with miscarriage risks. 
• Chromosomal issues – These can be caused by inherited chromosomal or genetic issues, or by balanced translocation, which occurs when a parent has a rearrangement of his or her chromosomes without experiencing any health issues. 
• Overactive immune system – Research is still delving into this area of fertility. It’s a hot topic amongst fertility specialists, and opinions vary country by country, but immunosuppressants are frequently given when recurrent miscarriages occur. 
• Anatomy – Structural abnormalities of the female reproductive organs are a recognized factor in recurrent miscarriage. These can include structural problems of the uterus, fibroids, adhesions and other acquired abnormalities, as well as a weakened cervix. 

Wider issues such as blood clots (i.e. thrombophilia) and infections (i.e. bacterial vaginosis) can also put mothers at higher risk of miscarriage, adds Dr Elenis. 

What are the warning signs?

The most common symptom of miscarriage is vaginal bleeding. According to Dr Elenis, this can range from light spotting, to brownish discharge, heavy bleeding and bright-red blood or clots, which can come and go over several days. However, it shouldn’t exceed a week.. 

“It’s important to remember that light vaginal bleeding is relatively common in the early stages of pregnancy, but don’t hesitate to contact your doctor if you feel concerned,” she adds. “You know your body, so always feel empowered to consult your physician whenever you feel it’s needed.”

Other common symptoms of early miscarriage include cramping, pain in the lower stomach, vaginal discharge, and no longer experiencing the symptoms of pregnancy (i.e. nausea, breast tenderness etc.). 

“If you experience any of these symptoms, consult your doctor sooner rather than later to ensure you’re looking after both your physical and mental wellbeing,” Dr Elenis tells Live Science. “And, if you’ve had more than two or three recurrent miscarriages and are worried, feel empowered to go straight to an early pregnancy unit for assessment.” 

Miscarriage vs period

Usually when we are pregnant, women do not have periods and are definitely unlikely to have a heavy period/ According to Dr Patel, if there is any bleeding in pregnancy, this is a concern and should be referred to your obstetrician or gynecologist.

“Generally speaking, bleeding associated with a miscarriage tends to get heavier and last longer than a typical period, and you may experience cramping as your cervix starts to dilate, which will likely be more painful or acute than typical period cramps,” says Dr Elenis. “Talk to your doctor about conducting tests to confirm your experience either way, so that you can find the best route forward based on your situation.”

How are miscarriages treated?

In many instances of early miscarriage, medical intervention isn’t necessary because the pregnancy tissue hasn’t built up in the womb, meaning there’s nothing left behind to remove. However, if tissues have built up and aren’t exiting the womb, then you will have a couple of different options, which may vary by country. 

“The safest thing is to let the miscarriage happen naturally,” says Dr Patel, ‘If this takes longer than the normal three to four weeks, then you need to see your doctor as there is a risk of infection and other complications developing.”

This first course of action is known as ‘expectant management. According to Dr Elenis, it entails waiting for the tissue to pass out of your womb naturally. This route usually applies to miscarriage in the first trimester, and entails waiting seven to 14 days after miscarriage for the tissue to pass. However this route can take some time, and involves risk of infection. 

“As such, expectant management can be challenging for many, as the anxiety and stress around waiting can do more harm than good,” she says. “It’s very important to make this decision with your healthcare provider based on your medical history, comfort levels, and personal preference. If you’re not comfortable with this approach, don’t hesitate to be vocal, and advocate for yourself until you find a solution that works best for you.”

It’s also common to treat miscarriage with medical management by taking medication, which spurs the womb to release pregnancy tissues. This treatment usually moves forward within two weeks of miscarriage if the tissues do not pass on their own, and the pessary-based medication usually kicks in within a few hours. 

“It works by opening the cervix, which allows the tissues to pass out of the womb, and will involve symptoms similar to a heavy period, with cramping and heavy vaginal bleeding being common, although bleeding can last up to three weeks,” explains Dr Elenis.

Surgical management is another option, which involves manually removing the tissue from the uterus. This option typically moves forward immediately if continuous bleeding, infection, or expectant management has proven unsuccessful. 

Surgery involves removing remaining tissue with a suction device, and will be performed under general or local anesthetic. Naturally, both treatments will be overseen by a doctor; some may involve a hospital stay, some may not — it’s often dependent on your situation and location.

So which treatment is safest and is there any risk? “The efficacy and safety of each procedure is dependent on each individual situation,” Dr Elenis tells Live Science. “Expectant management comes with the risk of infection but is often successful, and both medical and surgical management come with very little risk, while maintaining a high success rate.”

Taylor says: “It is completely normal to feel scared about your choices, just like with labor. No-one really knows how long these things will take, or if it will even happen at all. All the doctors can do is advise you on the safest options available to you at that time given the circumstances. It is a scary time and there are no hard and fast rules.”

It’s also very important to remember that while most treatment options focus solely on physical health, mental health care should be involved in your treatment plan – and dads-to-be need consideration too. 

“Miscarriage can take its toll the emotional and mental wellbeing of all involved, so don’t hesitate to seek out a therapist, confide in your support network, or seek out those who may have experienced similar situations to ensure you’re accessing comprehensive support,” Dr Elenis says. “Miscarriage is hard, and it’s not something you have to move past until you’re ready.”

The good news is that most couples who have experienced one or two miscarriages and who have no underlying medical problems, typically will go on to have a healthy, successful pregnancy.

What is a stillbirth?

Stillbirth is when a baby is born dead after 24 weeks of pregnancy. Dr Elenis says: “The fetus cannot be evacuated by medication, and requires medical intervention, which usually involves either dilation and evacuation (known as a D&E), induced labor, or a cesarean section to remove the baby and pregnancy tissues from the womb.”

In about half of all cases of stillbirths, no cause was found for the pregnancy loss, according to the National Institute of Child Health and Human Development (NICHD). 

Many of the possible health and lifestyle reasons for miscarriage we’ve just heard about also apply to a stillbirth. 

Other risk factors for stillbirth include placental problems, umbilical cord accidents, Rh disease (caused by a blood incompatibility between the mother and the fetus) and a lack of oxygen to the fetus during delivery.

Can you prevent a miscarriage?

Unfortunately there is no way to prevent a miscarriage once it has started. And while many women might experience feelings of guilt, shame and failure when they miscarry, it’s not their fault.  

• Read more: 6 myths about miscarriage 

The father-to-be’s grief and sadness is often dismissed by others after a miscarriage, with the focus on the woman. As you’d expect, pregnancy loss among lesbian relationships is just as devastating, and the couple might also face other stressors, for example, a lack of support from those who disapproved of them becoming parents in the first place.

“Alcohol, smoking, and recreational drug use have all been tied to increased miscarriage risk and should be avoided if you’re looking to conceive, or have had a miscarriage,” says Dr Elenis. “The same goes for consuming large amounts of caffeine, with current recommendations still focusing on limiting coffee consumption while pregnant, however the exact guidelines vary between countries. 

Some foods are often best avoided, too, as they can contain harmful bacteria — some cheeses and meat, for example, contain listeria which can bring on a miscarriage. Some medications can also increase the risk of miscarriage, so it’s always a good idea to look over any medication you might be taking and see if you need to seek out alternatives with your doctor, if you’re trying to get pregnant.

One study by the School of Public Health found that the risk of miscarriage might increase during the summer, but more research is needed to understand the potential roles of extreme heat and other environmental connections to pregnancy loss. 

Dr Patel says: “If you are concerned about miscarriage, have a family history of personal history, or just want to discuss how to plan a healthy pregnancy, I would advise you make an appointment with your doctor to help you plan this, to reduce risks.”

How long should you wait to try again after miscarriage?

The recommended time to wait before trying again after miscarriage in the U.S is three months, while the World Health Organization (WHO) guidance is six months.

However, this timeline was challenged by Dr Sohinee Bhattacharya’s scientific review, which found that women who tried to get pregnant again within six months cut their risk of a further miscarriage by a fifth. 

The meta-analysis examined 16 studies of 1.04 million women and the impact of falling pregnant within six months.

Other research published in the journal BMJ found that out of more than 30,000 respondents who had a miscarriage and then a healthy pregnancy, those who conceived within six months of the loss were less likely to miscarry again than those who waited.

If you are keen to try again after a miscarriage, speak to a medical professional first.

“It’s important to consult your doctor because every person’s situation is different, and this will help you pursue the option that’s best for your situation,” says Dr Elenis. “In general, you can typically start trying again once your bleeding has stopped, but this advice can differ, as some doctors recommend waiting until you’ve had your first period to try again.

“Take the time you need to heal, and remember it’s okay to feel like you need a break — losing a baby is never easy, no matter how far into the pregnancy you were, so don’t feel pressured to bounce back before you’re ready.”

Coping with miscarriage

When a pregnancy ends unexpectedly through a miscarriage, a woman's body may recover physically long before she heals from it emotionally. She may experience a range of intense emotions from guilt and sadness to anger and self-blame. 

"People get through a miscarriage, they don't get over it," says Kristen Swanson, a professor and dean of the college of nursing at Seattle University, who has researched the emotional consequences of miscarriage.

The majority of women find a point of resolution 12 weeks after a miscarriage, Swanson says. By about 12 weeks, if the good times in a day don't outweigh the bad, a woman should seek help for her pregnancy loss because her grief may be complicated by other things in her life.

In her own research, Swanson found that men tend to grieve immediately after a miscarriage, and the resolution of their grief is generally faster than a woman's. She said it's not uncommon for a man to feel as though he's not only lost a baby but to some extent, he has also lost his partner. 

When a woman receives safe and supportive care after a miscarriage — care that validates what she has been through and where her feelings receive a warm and gentle response — this can make a big difference to the way a woman moves through a pregnancy loss, Swanson said. 

Tips for partners, family and friends following a miscarriage

As a result of her research on women and miscarriage, Swanson developed a caring theory. This five-step process can be used by a partner, family, friends and health professionals in caregiving roles.  

• Knowing — Try hard to understand what it's like for the woman and couple going through a pregnancy loss and what this event might mean in their lives. 
• Being with — Be available and attentive, and allow a person to go through their emotional process, Swanson advises. 
• Doing for — Anticipate the small needs or kindnesses that may comfort a woman and make her feel safe. 
• Enabling — Help the individual get through this life transition by focusing on the event, being supportive, allowing and validating feelings, and giving feedback.  
• Maintaining belief — Sustain faith in a woman's ability to get through this difficult experience. Maintain a hope-filled attitude toward the future and offer realistic optimism. Even if a woman may be falling apart emotionally, recognize that there is a strong and capable person beneath, Swanson says. 

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

Additional resources

• The March of Dimes provides tips for women coping with grief following a miscarriage. 
• Miscarriage & Abortion Hotline operated by doctors who can offer expert medical advice: Available online or at 833-246-2632
• ACOG: Early Pregnancy Loss (Miscarriage)
• NICHD: Pregnancy Loss: Overview
• ASRM: What Is Recurrent Pregnancy Loss (RPL)?