Inclusion Criteria:  (1) The pregnant woman is born at term and has a single child; (2) Regular obstetric examination during pregnancy with complete obstetric examination data was diagnosed as gestational diabetes mellitus; (3) Pregnant women with body mass index (BMI) < 35kg/㎡; (4) All the operations were performed electively, and epidural anesthesia was used as the surgical anesthesia.  Exclusion Criteria:  (1) Pregnancy complicated with medical and surgical diseases, such as thyroid dysfunction and chronic hypertension; (2) Insufficiency of vital organ function or complicated tumor; (3) Pregnant women with other pregnancy complications besides GDM, such as preeclampsia, etc.; (4) The operation method is classical cesarean section or pregnant women with postpartum hemorrhage;