INS and type 2 diabetes mellitus: The meta-analysis by Butalia, including RCT in women with T2DM or GDM treated with metformin during pregnancy, showed that metformin, compared to insulin, lowered the risk of neonatal hypoglycemia (RR 0.63; 95% CI 0.45–0.87) and LGA babies (RR 0.80; 95% CI 0.64–0.99), while not increased the risk of preterm delivery (RR 1.18; 95% CI 0.67–2.07), SGA babies (RR 1.20; 95% CI 0.67–2.14), perinatal mortality (RR 0.82; 95% CI 0.17–3.92) in a short-term follow-up period [66].