Compared with insulin, metformin demonstrated a significant reduction in the risks of pre-eclampsia (RR 0.61), induction of labor (RR 0.90), CD (RR 0.91), macrosomia (RR 0.67), NICU admission (RR 0.75), neonatal hypoglycemia (RR 0.55), and LGA infants (RR 0.80, 95% CI 0.68 to 0.94, p  =  0.007). This evidence concerns the gene INS and Large for gestational age.