Myo-inositol may prevent gestational diabetes onset in overweight women: a randomized, controlled trial

Objective: To evaluate whether myo-inositol supplementation may reduce gestational diabetes mellitus (GDM) rate in overweight women. Methods: In an open-label, randomized trial, myo-inositol (2 g plus 200 μg folic acid twice a day) or placebo (200 μg folic acid twice a day) was administered from the first trimester to delivery in pregnant overweight non-obese women (pre-pregnancy body mass index ≥ 25 and < 30 kg/m2). The primary outcome was the incidence of GDM. Results: From January 2012 to December 2014, 220 pregnant women were randomized at two Italian University hospitals, 110 to myo-inositol and 110 to placebo. The incidence of GDM was significantly lower in the myo-inositol group compared to the placebo group (11.6% versus 27.4%, respectively, p = 0.004). Myo-inositol treatment was associated with a 67% risk reduction of developing GDM (OR 0.33; 95% CI 0.15–0.70). Conclusions: Myo-inositol supplementation, administered since early pregnancy, reduces GDM incidence in overweight non-obese women.