RESUMO
Metformin is recognized for its dual action in lowering blood glucose levels and enhancing insulin sensitivity, positioning it as the primary oral drug for managing type 2 diabetes mellitus (T2DM). Despite its ability to cross the placenta and expose the fetus, extensive clinical application has not revealed significant adverse effects. Metformin finds widespread application during pregnancy in conditions such as obesity, polycystic ovary syndrome, T2DM, and gestational diabetes mellitus. This article aims to establish an evidence-based perspective on the impact of metformin administered during pregnancy on maternal and fetal outcomes, as well as the long-term health of offspring. Generally deemed safe and effective, metformin is viewed as a means to control hyperglycemia and manage gestational weight gain without conspicuous adverse effects on maternal and fetal pregnancy outcomes. However, metformin alone may not suffice for achieving glycemic control, necessitating the addition of insulin. Besides, the long-term offspring risks of metformin exposure are controversial, long-term follow-up study is urgent to bring certainty into this field. Thus, tight control over indications for metformin use during pregnancy is crucial to ensure optimal maternal and fetal health outcomes. Although not suggested as a first-line agent for glycemic control in pregnancy, it may be considered as an adjunctive option in cases of severe insulin resistance or in low-resource areas where access to insulin is challenging.