INS and gestational diabetes: If the blood glucose level of pregnant women with GDM is high, the blood glucose will reach the fetus through the placenta; as a consequence, the fetal insulin level will rise and hyperinsulinemia will occur, which will have an inhibitory effect on the synthesis and release of lung surfactant, leading to the prolonged maturity of the fetal lung; also, the occurrence of RDS will increase 1 month after the neonate is born [11].