Investigation the Effects of Metformin versus Insulin on Neonatal and Maternal Outcomes in Women with Gestational Diabetes Mellitus: A Randomized Clinical Trail

The aim of this study was to evaluate the effectiveness of metformin versus insulin in the glycemic control and to investigate the maternal and neonatal outcomes in in women with gestational diabetes mellitus. Pregnant women with gestational diabetes were randomized to either receive metformin (n=70) or insulin (n=70). Inclusion criteria were singleton pregnancy, following healthy diet and performing exercise for at least one week without satisfactory blood glucose level, no risk factor contributing to lactic acidosis, and no anatomic and/or chromosome anomalies. Two patients were excluded from the study due to lost to follow-up. The mean score of BMI and FBS after treatment was similar between two groups. But, the mean score of 2 hours blood sugar in insulin group (104.38±7.06 mg/dl) was significantly higher than metformin group (97.5±5.98 mg/dl) (P<0.0001). The weight gain in metformin group was slightly lower than insulin group. (P=0.123). The proportion of neonatal hypoglycemia in insulin group was higher than metformin group (20 vs 3, P=0.002). Other neonatal outcomes such as IUGR, IUFD, fetal anomaly, polyhydramnios, macrosomia, oligohydramnios, and NICU stay did not differ significantly between two groups. In conclusion, metformin had compatible effect with insulin in decreasing adverse maternal and neonatal outcomes even in some parameters such as neonatal hypoglycemia it works better. Totally, metformin is safe and effectiveness in controlling the gestational diabetes mellitus.