INS and Large for gestational age: Compared with metformin, insulin had a significant increase in the gestational age at delivery (MD, 0.23; 95% CI, 0.12 to 0.34; P < 0.001); likewise, insulin had a risk of macrosomia (RR, 0.68; 95% CI, 0.55 to 0.86; P < 0.05).