Prenatal Antibiotics, C-Sections Pose Increased Risk for Childhood Obesity, Says New Study

During pregnancy, expectant mothers are often told what they should or shouldn’t do in order to keep their babies healthy. Now there might be two more items added to that already extensive list: antibiotics and cesarean section delivery.

Columbia University researchers have discovered a possible link between a mother’s antibiotic usage during pregnancy and an increased risk of obesity in the child she is carrying.

The research, published in the International Journal of Obesity, followed 436 healthy, non-smoking pregnant women, who had been recruited at a New York clinic between 1998 and 2006, until their children turned seven years old.

During the second and third trimesters of their pregnancies, 16% of those mothers used antibiotics. However, the study did not track what kinds of antibiotics they used or for what infections they had been administered, but it did allow for control for gestational age, birth weight, breastfeeding, the mother’s body mass index, socioeconomic status and other variables.

Overall, the results were consistent with previous studies that linked antibiotic usage in mothers with obesity in children. The new study found that antibiotic exposure increased the risk of obesity by 84% when compared with children who were not exposed to antibiotics.

The researchers speculated that the antibiotics could impact microbes in the body and come into contact with the fetus through the placenta. When the antibiotics kill off the natural, healthy bacteria in the colon, they can cause an imbalance that could lead to illness and increase a child’s chance of developing obesity and other conditions later on.

The study’s lead author, Noel Mueller, a postdoctoral research fellow at Columbia University’s Mailman School of Public Health and Institute of Human Nutrition, said the findings still warrant further research in order to study the links to childhood obesity.

Mueller also cautioned the overuse of antibiotics for some. “Our findings should not discourage antibiotic use when they are medically needed, but it is important to recognize that antibiotics are currently overprescribed,” he said in a press release.

A separate portion of the study unrelated to prenatal antibiotic usage associated C-section delivery with a 46% higher risk of childhood obesity. Researchers considered maternal age, ethnicity, birth weight, sex, breastfeeding in the first year, gestational antibiotic use and delivery mode in their analysis.

The researchers speculated that C-section births may also reduce the healthy transmission of bacteria from mother to child during delivery. Mueller called for strategies to give newborns “health-promoting bacteria” after “medically unnecessary C-sections.”