Does Metformin Have a Role in Managing Diabetes During Pregnancy?

Insulin is first-line pharmacotherapy for type 2 diabetes during pregnancy and for gestational diabetes when lifestyle modification has failed to optimize glycemic control. Two new trials address the potential role of metformin in these scenarios.

U.S. researchers randomized 800 insulin-treated pregnant adults (mean body-mass index, 36 kg/m²) with type 2 diabetes to receive either metformin (1000 mg twice daily) or placebo in addition to insulin. The groups did not differ in a composite of various neonatal complications (e.g., perinatal death, preterm birth, neonatal hypoglycemia), the primary outcome. However, metformin use was associated with significantly lower risk for a large-for-gestational-age infant (26% vs. 36%). Adverse events — ap…