Although at least 33 percent of U.S births are via cesarean birth (C-section), the latest study raises concerns over babies born via C-section and their risk of developing obesity or becoming overweight. According to the research, babies who are born via C-section are much more likely to become obese when they grow up as opposed to babies who are delivered vaginally.
Led by Dr. Jan Blustein, Ph.D., M.D., from the New York University of Medicine, the study analyzed data on a total of 10,2019 British-born children born between 1001 and 1992. Just over 9 percent of infants analyzed in the study were delivered via C-section. The aim of the study, published in the International Journal of Obesity was to "assess associations of C-sections with body mass from birth through adolescence." Blustien said, "there may be long-term consequences to children that we don't know" for children born via C-section and not vaginally delivered.
What's surprising is that, on average, infants delivered by C-section were born slightly smaller (by less than two ounces) than those infants who were delivered through the vaginal canal. Beginning around six weeks old, researchers found that C-section babies were consistently heavier than vaginally-born infants at almost all of their check-ins. Blustein and her colleagues reported that the link in weight gain was especially strong among children who were born to overweight mothers. For the entire study, rates of overweight and obesity ranged from 31 percent at 3-years-old to 17 percent at ages seven and 15.
The results of the study found that eleven-year-olds delivered by C-section were 83 percent more likely to be overweight or obese, compared to their vaginally-born peers. While Blustein said that the size of the obesity risk for kids is "not great," and shouldn't come into play for women who need a C-section for medical reasons, the findings of her study support the conclusions of nine previous studies, which has already found a link between C-sections and childhood obesity. However, "A woman who's considering C-section electively should probably know about those risks," she added.
Though research hasn't been able to prove whether a C-section is a reason some babies tend to gain more weight, Blustein does speculate that it might have something to do with the fact that C-section babies are missing out on important exposures to friendly bacteria during the trip through the birth canal. "The other possibilities," she said, "are (that) these are children that would have been heavier anyway," Blustein said.
As far as risk factors go due to the fact that overweight parents are more likely to have overweight children Blustein said, "Being heavy as a woman is a risk factor for C-section, so that's the problem with trying to figure out whether this is real or if it's simply a matter of selection." Her study was able to take a mother's weight into account and her team of researchers was able to find the link between C-section births and child obesity was "weak" among kids born to normal-weight mothers. Still, there could be unmeasured factors that exist to help explain the overall link between delivery method and child's weight. Said Blustein of the future work that has yet to be done, "This is certainly not the last word."
Could baby's weight be affected by delivery method?