By Mary Elizabeth Dallas
Women's weight before conception and how much they gain during pregnancy are known risk factors for gestational diabetes, the study authors explained. Gestational diabetes is a form of high blood sugar diagnosed during pregnancy. It can cause complications for both mother and baby.
Led by Linn Sorbye of the University of Bergen in Norway, researchers investigated the diabetes risk among women who had been pregnant once or twice before.
The study involved about 24,200 women who gave birth between 2006 and 2014. The researchers considered the women's previous history of gestational diabetes and body mass index (BMI) when they got pregnant again. BMI is an estimate of body fat based on weight and height. A BMI of 30 is considered obese.
About 36 percent of the women gained more than 1 BMI unit of weight between the start of their first pregnancy and their second, the study found. These women were more likely than women whose weight was stable to develop diabetes during a second pregnancy.
Women who gained twice as much weight had double the risk for gestational diabetes. And the risk rose fivefold for women who had the greatest weight gain, the researchers found.
These risks were most striking among women whose weights were normal before their first pregnancy. The study showed, however, that overweight women who lost weight after delivery reduced their risk of diabetes during another pregnancy.
The study was published Aug. 1 in the journal PLOS Medicine.