They don't have a higher proportion of body fat - rather, it seems that their bones, fat and tissues just grow much more than vaginally-born mice. The ecosystem of microbes that live inside us has been implicated in a range of health issues, so this may explain why babies born by C-section are more likely to grow up overweight, and to develop allergies and asthma in later life.
A new study finds that children who are born via c-section are more likely to become obese than those born naturally.
The study was conducted by the New York University. C-sections, however, have increased, with doctors in some regions of the world performing them 43 percent of the time.
Dominguez-Bello: We found that vaginally born mice have increased Bacteroides, Ruminococcaceae, and Clostridiales compared to mice delivered by C-section.
RG: Do you recommend women avoid C-section births?
For this study, researchers observed the effect of c-section birth on 34 mice and the effect of a normal birth on 35 other mice.
The new research was conducted on mice after which it was confirmed that the weight gain is linked to the impact of C-section birth on gut bugs. While the C-section males were around 20 per cent heavier than their vaginally-born counterparts, the females were 70 per cent heavier, she says. The microbiomes of the C-section mice didn't change structurally or mature to resemble those of older mice in the six weeks after the mice were born. By the time the mice had grown into adults 15 weeks later, there were stark difference in body weight between the two groups. She studies the microbiome and preterm birth in humans, and notes that it is hard to say what the new results mean for people.
The microbiomes of the C-section mice also looked different to those born vaginally. No wonder women choose to have C-sections. One is that they did not use perinatal antibiotics, but the team expects that antibiotics, combined with C-section, could contribute to the weight gain.