Management of Gestational Diabetes Mellitus: Metformin versus Insulin: A Systematic Review

Abstract

Introduction: Gestational diabetes mellitus (GDM) requires treatment to reduce adverse perinatal outcomes. Insulin has been the standard therapy, but the oral agent metformin is increasingly used. This review compares the safety and efficacy of metformin and insulin for GDM.

Methods: A search of MEDLINE and CENTRAL was conducted for RCTs comparing metformin to insulin for the treatment of GDM. Primary outcomes were glycemic control, and maternal and neonatal outcomes such as hypertensive disorders and large for gestational age (LGA) infants.

Results: The meta-analysis of 18 RCTs showed no significant difference in glycemic control or the incidence of LGA infants between the metformin and insulin groups. However, women in the metformin group had less gestational weight gain and a lower risk of pregnancy-induced hypertension. A significant portion of women on metformin required supplemental insulin.

Discussion: Metformin is a safe and effective oral alternative to insulin for the management of GDM, with some maternal benefits. The need for supplemental insulin in many patients should be discussed during counseling.

Conclusion: Metformin is a valid alternative to insulin for the primary treatment of gestational diabetes.