Big Babies: Are Heavier Newborns Healthy?

baby girl crib
Credit: Dreamstime

A newborn in Texas has tipped the scales at just over 16 pounds at birth. But is giving birth to such a burly baby healthy?

While we often hear about the health risks babies face when they are born too small, large babies face health complications as well, experts say.

"Bigger is not always better when it comes to babies' birth weight," said Dr. Kristin Atkins, a specialist in maternal and fetal medicine at the University of Maryland School of Medicine.

And the Texas newborn is just the latest example of a growing trend of bigger babies in the United States, a trend that can be partly attributed to the obesity epidemic, experts say.

Risks to baby and mom

Physically, if a baby is too large, his shoulders can become trapped under the mother's pelvic bones. This can damage the nerves in his neck, or break his collarbones or arms, Atkins said. Large babies may also need help breathing and have abnormally thick heart muscles, Atkins said.

There may even be a risk for brain damage, said Dr. Salih Yasin, an associate professor and vice chairman of obstetrics and gynecology at the University of Miami School of Medicine.

Big babies are often born to mothers who have gestational diabetes, Atkins said, as was the case for the mother of the jumbo Texas baby.

"The main nutrient that controls babies' growth is sugar," Atkins explained. "Therefore, mothers with diabetes that have elevated blood sugars are more likely to have big babies," she said.

In the womb, these babies are accustomed to a high level of sugar, but when they are born, this source of fuel is cut off, Yasin said. As a result, large babies tend to have low blood sugar and need to be monitored closely after birth, Yasin said. They are also at increased risk for jaundice, he said.

Later in life, these babies face an increased risk for obesity, diabetes and metabolic syndrome, Atkins said.

Women who deliver large babies vaginally are at risk for birth-related injuries, including tears of the vagina and rectum, Atkins said.

Obesity epidemic

The size of babies has increased in the United States in the last few decades, Yasin said. This may be partly due to the increase in rates of obesity and diabetes in the country, Yasin said. An obese woman has double or triple the risk of developing gestational diabetes during pregnancy compared with women who are not obese, he said.

Obese mothers often have to give birth by cesarean section, a surgical procedure that can present complications in and of itself, said Dr. Raul Artal, chairman of the Department of Obstetrics/Gynecology and Women's Health at St. Louis University.

Today, 50 percent of all mothers are overweight or obese, Artal said.

Obese mothers should avoid excessive weight gain in pregnancy, gaining no more than 10 pounds, to lower their risk of gestational diabetes and giving birth to a large baby, Artal said.

"The best way for women to prevent big babies is to monitor what they eat and control diabetes if they are diagnosed with diabetes in pregnancy," Atkins said.

Pass it on: Large babies, and the mothers that birth them, face a number of health complications.

This story was provided by MyHealthNewsDaily, sister site to LiveScience. Follow MyHealthNewsDaily staff writer Rachael Rettner on Twitter @RachaelRettner.

Rachael Rettner

Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.