Increasing the Body Mass Index (BMI) above one unit from first to second pregnancy increases the risk of gestational diabetes mellitus (GDM) in women, no matter if you are overweight or not, according to a Norwegian study performed at the University of Bergen and published in PLOS Medicine .
Women who were overweight at first pregnancy had the highest risk of GDM. However, the strongest risk, associated with weight gain between pregnancies, was found in women with BMI less than 25 in first pregnancy.
The well-known adage of losing weight having a beneficial effect was also visible as researchers found a reduced risk of GDM in overweight women who reduced their BMI more than two units from first to second pregnancy. Overweight is defined as BMI of 25 kg/m2 or more.
