COMPARATIVE STUDY OF INSULIN AND METFORMIN IN GESTATIONAL DIABETES MELLITUS

Background: Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with adverse maternal and neonatal outcomes. Insulin is the standard pharmacological treatment, but its limitations prompt the need for effective oral alternatives. Metformin, an insulin sensitizer, has gained attention for its potential to provide comparable glycemic control with added benefits in terms of patient compliance, cost, and safety. Objective: To compare the efficacy of metformin and insulin in reducing fasting blood glucose levels in pregnant women diagnosed with GDM. Methods: This randomized controlled trial was conducted in the Department of Obstetrics and Gynecology, Saidu Group of Teaching Hospital, Swat. A total of 260 women diagnosed with GDM at 24–33 weeks of gestation were randomized into two equal groups. Group A received oral metformin (500 mg BD, titrated to 1500 mg/day), and Group B received regular plus NPH insulin in BD dosing. The primary outcome was the mean reduction in fasting blood sugar (FBS) after two months of treatment. Data were analyzed using SPSS v22.0, with independent t-tests applied to compare outcomes. Results: Both groups showed significant reductions in FBS from baseline. Group A (metformin) had a mean pre-treatment FBS of 152.6 mg/dl and post-treatment FBS of 106.4 mg/dl, while Group B (insulin) had 153.1 mg/dl and 108.8 mg/dl, respectively. The mean reduction in FBS was slightly higher in the metformin group (46.2 mg/dl vs. 44.3 mg/dl), though the difference was not statistically significant (p > 0.05). No major adverse events were reported. Conclusion: Metformin demonstrated comparable efficacy to insulin in managing fasting blood glucose levels in GDM, making it a viable and patient-friendly alternative, especially in resource-limited settings.