BOSTON -- September 7, 2016 -- Babies born by caesarean delivery were 15% more likely to become obese as children than individuals born by vaginal birth, and the increased risk may persist through adulthood, according to a study published online by JAMA Pediatrics.
In addition, babies born via caesarean delivery were 64% more likely to be obese than their siblings born by vaginal birth.
The researchers also found that individuals born via vaginal birth among women who had undergone a previous caesarean delivery were 31% less likely to become obese compared with those born via caesarean birth following a caesarean birth.
“Caesarean deliveries are without a doubt a necessary and lifesaving procedure in many cases,” said senior author Jorge Chavarro, MD, Harvard T.H. Chan School of Public Health, Boston, Massachusetts. “But caesareans 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.”
While a number of previous studies have suggested a link between caesarean delivery and a higher risk of obesity in offspring, the studies were either too small to detect a clear association or lacked detailed data.
The current analysis included 16 years’ worth of data from more than 22,000 young adults in the Growing Up Today Study (GUTS), in which participants answered survey questions every year or 2 years from 1996 to 2012. The researchers looked at the participants’ body mass index (BMI) over time; at whether or not they were delivered via caesarean (using information collected from participants’ mothers, participants in the Nurses’ Health Study II); and at other factors that could play a role in obesity, such as the mothers' pre-pregnancy BMI, smoking status, age at delivery, and where they lived. They also looked at whether the mothers had previous caesarean deliveries.
“I think that our findings -- particularly those that show a dramatic difference in obesity risk between those born via caesarean and their siblings born through vaginal delivery -- provide very compelling evidence that the association between caesarean birth and childhood obesity is real,” said Dr. Chavarro. “That's because, in the case of siblings, many of the factors that could potentially be playing a role in obesity risk, including genetics, would be largely the same for each sibling -- except for the type of delivery.”
SOURCE: Harvard T.H. Chan School of Public Health