Is metformin safe in pregnancy: a focus on offspring outcomes

Introduction Metformin has been part of treatment algorithms for type 2 diabetes mellitus (T2DM) for decades. While it has formal approval in the U.S.A. for treatment of T2DM, it is used off-label in gestational diabetes mellitus (GDM), polycystic ovarian syndrome (PCOS), and ovarian hyperstimulation prevention. Its role as an insulin sensitizer has made it an attractive therapeutic to address the insulin resistance seen in these syndromes. In 2022, the European Union approved metformin as the only oral antidiabetic medication for diabetes in pregnancy. While its safety and benefits for the mother are well documented, it does cross the placenta with plasma concentrations comparable between mother and child at delivery.