Metformin in women at high risk of gestational diabetes mellitus

The prevalence of gestational diabetes mellitus (GDM) is increasing worldwide. Attempts at reducing adverse pregnancy outcomes through dietary and lifestyle interventions have shown modest effects, with no significant impact on GDM incidence or related outcomes.
Metformin increases insulin sensitivity and decreases hepatic glucose production. In pregnancy, metformin might reduce insulin resistance, causing a reduction in maternal glucose levels and, consequently, fetal hyperinsulinaemia. This could have a positive effect on GDM incidence and related adverse outcomes. Two double-blind randomized controlled trials – the Efficacy of Metformin in Obese Pregnant Women, a randomised controlled (EMPOWaR) trial and the Metformin in Obese Pregnant Women (MOP) trial – showed no significant effects of metformin on birth weight percentiles in obese pregnant women. Thus, our present study investigated the effects of metformin in obese pregnant women, but also in women with other risk factors for GDM.