Neonatal outcomes in women with gestational diabetes mellitus treated with metformin in compare with insulin: A randomized clinical trial

Background: The objective of this study was to compare neonatal outcomes in women with gestational diabetes mellitus (GDM) treated with either metformin or insulin. Materials and Methods: A randomized clinical trial carried out on year 2011 on 109 women with GDM who did not adequately control by dietary measures. They received metformin 500 mg once or twice daily or insulin 0.2 IU/kg/day initially. The dose was titrated to achieve target blood glucose values. Neonatal outcomes such as hypoglycemia, birth weight, Apgar score, umbilical artery pH, and hyperbilirubinemia in the 50 women who remained exclusively on metformin were compared with 50 women who treated with insulin. Results: Two groups were similar in mean fasting blood sugar (P = 0.7) and postprandial measurements (P = 0.8) throughout GDM treatment. Pregnancy complications or preterm labor were not different significantly between two groups. Considering neonatal outcomes between insulin and metformin groups, such as hypoglycemia (2 [4%] and 0 [0%], respectively), birth weight (3342 +/- 506 mg and 3176 +/- 438 mg, respectively), 5th min Apgar score <7 (no one in either group), umbilical artery pH <7.05 (no one in either group) and hyperbilirubinemia (1 [2%] and 0 [0%], respectively), no significant statistical differences were seen. Conclusion: Based on these preliminary data, considering neonatal outcomes, metformin appears to be a safe as insulin in the treatment of GDM.