A pregnant woman's higher blood sugar level is linked to a significantly greater long-term risk of obesity in her child, according to a large international study led by Northwestern University (NU).

The higher the woman's blood sugar is, the greater the risk of her child being obese.

Moreover, mothers with higher-than-normal blood sugar during pregnancy also were significantly more likely to develop type 2 diabetes a decade after pregnancy than their counterparts without high blood sugar.

The Hyperglycemia and Adverse Pregnancy Outcomes-Follow-Up Study (HAPO-FUS) evaluated children 10 to 14 years after birth in 10 clinical centers in seven countries and regions: the United States, Canada, Israel, Britain, Chinese Hong Kong, Thailand, and Barbados. The study included 4,697 moms and 4,832 children.

The researchers used multiple methods to determine degrees of overweight or fatness in the child. Clinical sites used a bod pod that more accurately calculates the percent of fat tissue. In addition, investigators measured the waist or hip as well as the thickness of the skin folds, which all correlate with how obese someone is.

"The children of moms with gestational diabetes and higher blood sugar were higher in all these categories," said corresponding study author Boyd Metzger, professor emeritus of medicine in endocrinology at NU Feinberg School of Medicine.

"The HAPO-FUS results are important because they demonstrate that even women with mild hyperglycemia during pregnancy and their offspring are at risk of harmful maternal and child health outcomes, potentially increasing the number of women and children at risk of acquiring lifelong chronic medical conditions," said study coauthor Wendy Brickman, an associate professor of pediatric endocrinology at Feinberg.

"Research is needed to identify interventions that will improve the health outcomes of these women and children," Brickman added.

The study was published in JAMA on Sept 11.