Metformin and insulin in the management of gestational diabetes mellitus: preliminary results of a comparison

Abstract

Objective: To compare glycemic control and neonatal outcomes in women with gestational diabetes mellitus (GDM) treated with metformin vs. insulin.

Study design: Women with GDM not controlled with diet and exercise were randomized to metformin (n = 32) or insulin (n = 31). The levels of glycemic control as well as maternal/neonatal complications were evaluated.

Results: The mean (+/- SD) fasting and 2-hour postprandial blood glucose did not differ statistically between the 2 treatment groups. No patient failed metformin and required insulin. The majority (27/32) were easily controlled on the initial dosage (500 mg twice a day). Gestational age at entry and delivery (p = 0.077, 0.412) were similar. The difference in the rate of cesarean delivery was not statistically significant between the 2 groups (p = 0.102). Neonatal statistics were also not different between the metformin and insulin groups: birth weight, Apgar score at 5 minutes, respiratory distress syndrome, hyperbilirubinemia, neonatal hypoglycemia and neonatal intensive care unit admission (p = 0.144-0.373).

Conclusion: Based on these preliminary data, metformin appears to be an effective alternative to insulin in the treatment of GDM.