Use of antibiotics during pregnancy does not appear to affect children’s weight in subsequent years, but use during infancy may increase their risk of becoming overweight or obese. The findings come from an analysis published in the journal Obesity.

When investigators examined all relevant published studies that looked at the use of antibiotics during pregnancy or infancy and children’s later weight—which included 23 observational studies involving 1,253,035 participants—they did not find a link between prenatal antibiotic use and childhood overweight or obesity. An increased risk of overweight or obesity was seen in analyses limited to the use of antibiotics in the second trimester, however, as well as in the use of antibiotics during infancy.

“Antibiotics should be used more cautiously for children than pregnant women,” said senior author Yong Xu, MD, PhD, of The Affiliated Hospital of Southwest Medical University, in China.