Pharmacologic Treatment of Diabetes in Pregnancy

Diabetes affects 6% to 9% of pregnancies, with gestational diabetes mellitus accounting for more than 90% of cases. Pregestational and gestational diabetes are associated with significant maternal and fetal risks; therefore, screening and treatment during pregnancy are recommended. Recommendations regarding the preferred treatment of diabetes in pregnancy have recently changed, with slight differences between American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) recommendations.

Our review discusses the diagnosis, management, and treatment of pregestational and gestational diabetes with the oral hypoglycemic agents metformin and glyburide as well as insulin. We also review the evidence for the safety and efficacy of these medications in pregnancy.

Articles were obtained from PubMed, the ACOG Practice Bulletin on Gestational Diabetes Mellitus, and the SMFM statement on the pharmacological treatment of gestational diabetes.

Insulin does not cross the placenta and has an established safety profile in pregnancy and is therefore considered a first-line treatment for gestational diabetes. Metformin and glyburide have also been shown to be relatively safe in pregnancy but with more limited long-term data. Regarding maternal and fetal outcomes, metformin is superior to glyburide and similar to insulin.

Insulin is the preferred pharmacologic treatment according to ACOG. However, SMFM has stated that outcomes with metformin are similar, and it may also be considered as first-line therapy. Both agree that the available data show that metformin is safer and superior to glyburide, and glyburide is no longer recommended as a first-line therapy for the treatment of gestational diabetes.