Metformin in obstetric and gynecologic practice: a review.

Metformin is a common treatment for women who have insulin resistance manifesting as type 2 diabetes or polycystic ovarian syndrome (PCOS). With an increasing number of these patients conceiving, it is expected that the use of metformin in and around the time of pregnancy will increase. This article reassesses the mechanisms, safety, and clinical experience of metformin use in obstetrics and gynecology. Metformin is an attractive therapeutic option because administration is simple, hypoglycemia rare, and weight loss promoted. There is a large volume of research supporting the use of metformin treatment in diabetes mellitus, androgenization, anovulation, infertility, and recurrent miscarriage. Although metformin is known to cross the placenta, there is, as yet, no evidence of teratogenicity. Metformin has an array of complex actions, accounting for the varied clinical roles, many of which are still to be fully evaluated. Much research is still needed.