Study: Obesity Risk Doubled in Babies Born via C-Section


New research suggests that babies born via c-section may have an increased risk of becoming obese by age 3. The study, published in  The Archives of Disease in Childhood, has drawn some attention this week.

Researchers tracked 1,255 pregnant women, 284 of whom gave birth via c-section. By age 3, 15.7% of the kids born via c-section were obese, compared to only 7.5% of the kids born vaginally. That’s double the odds of obesity when born via c-section.

There was no difference between planned and unplanned c-sections. And since factors such as maternal weight, duration of breastfeeding, socioeconomic circumstances and other aspects of maternal health were controlled for, the researchers looked for another factor that might explain the increase. And they came up with … bacteria.

Babies born vaginally are exposed to mom’s bacteria via the birth canal. This bacteria is the first the baby encounters. And apparently it’s a perfect blend to colonize the baby’s gut in such a way that might protect the baby from infection and possible play a role in future weight gain. Authors of the study also wonder if the mode of delivery has an impact on endocrine function, which could affect weight.

Lead author, Dr. Susanna Y. Huh, an assistant professor of pediatrics at Harvard, said, “”Those mothers who are considering C-section in the absence of a medical indication should be counseled about this potential risk.”

Meredith Fein Lichtenberg, a birth and breastfeeding expert, made the following sage observation on her excellent blog A Mother Is Born: “There is much we do not understand.  When it comes to a body that is healthy, we should be very reserved about elective surgeries.  And we ought to manage labors to minimize the likelihood of c-section, not just for all the reasons we know, but, even more, for the reasons we don’t know yet.”

It’s a small study and the results merely suggest a connection. But the emerging research into how the newborn gut is colonized is fascinating— we’re so often taught that bacteria is bad, but it’s also good. And apparently the bacteria on and around the mother (her vagina, her skin, her milk, her mouth) can be hugely beneficial, possibly laying the foundation for a lifetime of health. Nature can be very clever like that.


photo: Bianca Jae/Flickr