Individuals born by cesarean delivery were 15 percent more likely to become obese as children than individuals born by vaginal birth—and the increased risk may persist through adulthood, according to a large new study from Harvard T.H. Chan School of Public Health. In addition, individuals born via cesarean delivery were 64 percent more likely to be obese than their siblings born by vaginal birth.
The study will be published online September 6, 2016 in JAMA Pediatrics.
The researchers also found that individuals born via vaginal birth among women who had undergone a previous cesarean delivery were 31% less likely to become obese compared with those born via cesarean birth following a cesarean birth.
“Cesarean deliveries are without a doubt a necessary and lifesaving procedure in many cases,” said Jorge Chavarro, associate professor of nutrition and epidemiology at Harvard Chan School and senior author of the study. “But cesareans also have some known risks to the mother and the newborn. Our findings show that risk of obesity in the offspring could another factor to consider.”
Nearly 1.3 million cesareans are performed each year in the U.S., accounting for one third of all deliveries. While a number of previous studies have suggested a link between cesarean delivery and a higher risk of obesity in offspring, the studies were either too small to detect a clear association or lacked detailed data.