The difference between a cesarean section at 38 and 39 weeks of gestation is the maturity of the fetal lungs and the safety for the fetus and the mother. 1. Fetal lung maturity: Fetal lung maturity often develops more maturely at 34 weeks, but the fetal lung maturity at 38 weeks is lower than that at 39 weeks. Therefore, without special circumstances, cesarean section should be performed after 39 weeks, when the fetal lungs are fully developed. 2. Safety: The probability of fetal lung disease after cesarean section at 38 weeks is greater than that of cesarean section at 39 weeks. Therefore, if there is no emergency, patients undergoing elective surgery should be kept pregnant until 39 weeks. However, patients with uterine disease, such as keloid uterus and thin scar, should not wait too long, and it is safer to deliver by cesarean section at 38 weeks to avoid uterine rupture due to uterine contractions. The optimal time for cesarean section should be decided based on a standardized assessment of the fetus and the mother’s physical condition, and treatment should be in accordance with medical advice.