13 Jan 2024 • Insulin is first-line pharmacotherapy for type 2 diabetes during pregnancy and for gestational diabetes when lifestyle modification has failed to optimize glycemic control.

In two randomized trials, researchers evaluated adding metformin to standard care.

• U.S. researchers randomized 800 insulin-treated pregnant adults 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%)

• In another trial, Irish researchers randomized 500 women with newly diagnosed gestational diabetes to receive lifestyle modification and either metformin (maximum dose, 2500 mg daily) or placebo. The groups did not differ significantly in a composite of insulin initiation or fasting glucose level ≥92 mg/dL at 32 or 38 weeks' gestation (the primary outcome). However, metformin users were significantly less likely to initiate insulin (38% vs. 51%) and less likely to have a large-for-gestational-age infant (7% vs. 15%).

These trials add to a growing body of evidence showing the safety of metformin during pregnancy. In patients who can't or won't use insulin (the standard of care), metformin appears to be a reasonably safe alternative.

Source: NEJM Journal Watch | Read full story