Background <p>Gestational Diabetes Mellitus (GDM) is linked with a multitude of adverse perinatal outcomes. There is a want for standard guidelines regarding the usage of Metformin in GDM. We aimed to study the perinatal outcomes in women diagnosed with GDM treated primarily with Metformin with or without Insulin.</p> Methods <p>We conducted a randomized controlled pilot study. with a total of 75 women, divided into three groups: GDM treated with Metformin with or without Insulin (Group M), GDM on Insulin alone (Group I), and healthy pregnant women as controls (Group H), with 25 subjects in each group. At delivery, fetal and maternal outcomes were documented.</p> Results <p>The mean age in groups M, I and H were 27.4, 26.2, and 27.3 years respectively. The baseline mean HOMA-IR were 3.9 and 4.1 for Group M and Group I, respectively (<i>p</i>-0.560). The mean fetal birth weight was 2.95 ± 0.54&#xa0;kg, 2.8 ± 0.41&#xa0;kg, and 2.97 ± 0.65&#xa0;kg in Groups M, H, and I, respectively (<i>p</i> = 0.527). The mean newborn HOMA-IR in Groups M and I was 1.8 ± 0.4 and 1.7 ± 0.5, respectively (<i>p</i> = 0.185). The adverse events in newborns were 20% (<i>n</i> = 5), 16% (<i>n</i> = 4) and 16% (<i>n</i> = 4) in Groups M, H, and I respectively (<i>p</i> = 0.403). The incidence of caesarean deliveries was 40% (<i>n</i> = 10), 48% (<i>n</i> = 12) and 24% (<i>n</i> = 6) in Groups M, H, and I respectively (<i>p</i>-0.253).</p> Conclusion <p>The study revealed identical maternal and fetal outcomes in women treated with Metformin as the primary drug compared to conventional treatment with Insulin in GDM.</p>