“There are differences in body composition, already at birth between obese women’s babies and normal weight women’s babies,” Emma Carlsen told Reuters Health in an email.
She led the study at Hvidovre Hospital at the University of Copenhagen in Denmark.
“It is important to notice that our study does not examine if there are any long term implications of these findings, and, therefore, follow-up studies are needed,” Carlsen said.
Among adults, having more belly fat is linked to a greater chance of developing high blood pressure, type 2 diabetes and heart disease.
“We don’t know if fat location in infants is important, although our finding is interesting,” Carlsen said.
She and her colleagues recruited 231 obese and 80 normal-weight mothers who had participated in a prior study on obesity in pregnancy.
They measured the women’s newborns and assessed their body composition using so-called dual-energy X-ray absorptiometry, or DXA scanning.
The researchers found that infants born to obese mothers were on average more than 6 ounces heavier at birth with 2.5 percent more body fat than infants whose mothers were of a healthy weight.
What’s more, babies born to obese mothers had about half an ounce more fat around their bellies, according to findings published in Acta Paediatrica.
Babies whose mothers gained more weight during pregnancy also tended to be born with more fat, regardless of the mother’s pre-pregnancy weight.
“This is a relatively small study, and it can be hard to extrapolate findings – however it adds to a growing body of evidence that shows differences in body composition in babies born to obese mothers,” Sian Robinson told Reuters Health in an email.
Robinson, who has studied infant and childhood obesity at the University of Southampton in the UK, wasn’t involved in the current research.
“To date there have been relatively few studies of body composition determined using DXA and we don’t yet know what the differences described in babies signify in later life,” she said.
Robinson’s own work has suggested that children’s body composition may change more over the first few years of life than later in childhood. But longer-term research is needed, she said.
Currently there is a lot of interest in whether excess weight gain during pregnancy can be prevented, Robinson added.
But, Carlsen said, “Our study indicates that it might be more effective to lose weight before becoming pregnant than to restrict gestational weight gain, if you want to affect offspring body composition.”
According to the American College of Obstetricians and Gynecologists, doctors should encourage obese women to lose weight through diet, exercise and behavioral changes before becoming pregnant.