Is metformin a safe alternative for GDM?

Insulin is the mainstay of treatment for women with gestational diabetes mellitus (GDM) who have failed lifestyle and diet interventions, with metformin use remaining controversial because of its ability to cross the placenta.

However, using metformin would avoid the obesogenic effects of insulin if it could be proven safe for the fetus.

The Metformin in Gestational Diabetes trial among Australian and NZ women with GDM showed that metformin is as safe and effective as insulin for both the fetus and the mother