INS and Hypoglycemia: Unlike insulin, metformin lowered neonatal birth weights (mean difference − 122.76 g; 95% confidence interval [CI] − 178.31, − 67.21; p < 0.0001), the risk of macrosomia (risk ratio [RR] 0.68; 95% CI 0.54, 0.86; p = 0.001), the incidence of neonatal intensive care unit admission (RR 0.73; 95% CI 0.61, 0.88; p = 0.0009), and the incidence of neonatal hypoglycemia (RR 0.65; 95% CI 0.52, 0.81; p = 0.0001).