It's common knowledge that women who become diabetic, or gain too much weight during pregnancy, risk delivering larger than usual babies. Furthermore, such babies are at greater risk of becoming obese later in life. But questions remain: What effects, if any, do mothers' gestational diabetes or weight gain have on their babies of normal weight? Are these infants also at increased risk of obesity later on?
These questions were addressed by researchers from Kaiser Permanente. Their study, "Impact of Maternal Glucose and Gestational Weight Gain on Child Obesity over the First Decade of Life in Normal Birth Weight Infants," was just published in the Maternal and Child Health Journal.
Led by Dr. Teresa A. Hillier, the group analyzed data from over 24,000 mothers and their babies, born between 1995 and 2003. Of these babies, over 13,000 were born in the normal weight range (5.5-8.8 pounds), and comprised the subjects of the study.
The normal-birthweight babies were followed for 10 years. Between the ages of 2 and 10 their height and weight were measured annually. These data formed the bases of gender-specific BMIs: Children whose BMIs were in the 85th to 94th percentile were considered overweight. Those at or above the 95th percentile were considered to be obese.
The findings: If the mothers had higher than normal blood glucose levels (but not frank gestational diabetes) and had gained more than the recommended amount of weight (over 40 pounds), the children were at increased risk for obesity by 10 years of age.
This effect also held true when the effects of maternal glucose levels and weight gain were considered independently. For example, children whose mothers gained more than 40 pounds during pregnancy were at least 15 percent more likely to become overweight or obese by age 10 years than kids whose mothers gained less than that. Also, those children of mothers who had the highest levels of blood glucose during pregnancy had a 30 percent greater risk of overweight or obesity than the children of mothers with normal blood sugar.
Dr. Hillier explained, "When women have elevated blood sugar and gain excess weight during pregnancy, it seems to change the baby's metabolism to 'imprint' the baby for childhood obesity. ... We need to intervene during the mom's pregnancy to help her with nutritional and lifestyle changes that will result in healthy weight gain, healthy blood sugar and ultimately, healthy children."
These findings could represent a very important step in gaining control over the unacceptable rates of obesity and diabetes in the country.