Large babies born to moms with gestational diabetes face nearly triple the risk of childhood obesity: study

Results highlight importance of weight management and blood sugar control during pregnancy to future health of children, say U of A researchers.

The size babies are at birth and whether their mother has maternal diabetes greatly increases the risk of children being overweight or obese, according to University of Alberta research.

Children who were larger than average at birth and whose mothers developed gestational diabetes (diabetes during pregnancy) had a 43 per cent rate of being overweight or obese-2.8 times the likelihood of being obese among average-sized babies born to moms without diabetes.

"In children who were born large and whose mothers had diabetes before they became pregnant, rates of overweight or obesity were 36 per cent higher," said Padma Kaul, professor in the Department of Medicine and adjunct professor in the School of Public Health.

Even with no maternal history of diabetes, noted Kaul, 35 per cent of children who were born large-generally over 4.5 kilograms or 9.9 pounds-remained overweight or obese by the time they had their preschool vaccinations.

Being born large appeared to be a bigger marker of risk than maternal diabetes status. The risk of obesity in children who were born average size of mothers who had gestational or pre-existing diabetes was 16 per cent and 15 per cent respectively. However, children who were born large had a 39 per cent risk of being overweight or obese.

The Diabetelogia study involved more than 81,000 children born to mothers in Alberta. Each child's weight was checked at their preschool immunization visit, between four and six years of age. This is one study of a larger program of research into diabetes and pregnancy that Kaul and her team are conducting at the U of A.

"This is one of the first studies to look at a large sample at the population level. With diagnosis of gestational and pre-existing diabetes on the rise, it's really important to raise awareness around healthy eating, nutrition and diabetes management for mothers," said Kaul.

"We hope that these findings will reinforce public health campaigns advising women who are planning to get pregnant that, just like smoking, alcohol consumption and other lifestyle choices, their weight prior to getting pregnant, and weight gain and blood sugar control during pregnancy, may have a significant impact on the future health of their children," noted the researchers in the study.

Benefit of breastfeeding

In some good news, breastfeeding in the first five months of life was associated with an approximately 25 per cent lower likelihood of being overweight or obese in childhood, and in all groups except mothers with large babies at birth and gestational diabetes or pre-existing Type 1 or Type 2 diabetes.

"We don't know why the protection offered by the breast milk did not extend to babies born to moms with diabetes. More research is needed."

The research was funded by the Canadian Institutes of Health Research.