Metformin prevents excessive weight gain in obese women with gestational diabetes

Overweight or obese women with gestational diabetes mellitus (GDM) may fare well with metformin treatment, which is reported in a recent study to safely and effectively prevent excessive and promote adequate gestational weight gain (GWG) independent of age, body mass index (BMI) and timing of GDM diagnosis, among others.

The retrospective study included 457 pregnant women with GDM and pregestational overweight or obesity, among whom 177 (38.7 percent) were treated with metformin. Treated women received the drug from a mean of 28 weeks of gestation until delivery at a mean dose of 2,100 g/day.

Treated vs untreated women had higher pregestational weight (mean, 86.1 vs 78.5 kg; p<0.001) and BMI (mean, 32.67 vs 30.10 kg/m²; p<0.001), and more often presented with obesity grades 2 (20.9 percent vs 7.5 percent; p<0.001) and 3 (9.0 percent vs 3.9 percent; p<0.001).

In a propensity-matched analysis of 130 metformin-treated and 130 untreated patients, metformin was associated with significantly less excessive GWG (29.23 percent vs 42.31 percent; odds ratio [OR], 0.56, 95 percent confidence interval [CI], 0.34–0.94; p=0.028) and more adequate GWG (36.92 percent vs 23.08 percent; OR, 1.95, 95 percent CI, 1.14–3.35; p=0.015).

There were no significant between-group differences observed in terms of glycaemic control, rate of insulinization, and obstetric, foetal and neonatal outcomes.

The findings indicate that metformin may play an important role in the management of excessive GWG in overweight or obese women with GDM, according to the researchers.