The best time to deliver a second child by cesarean section is around 39 weeks if the first child is delivered by cesarean section and the second child is a scarred uterine pregnancy. If the cesarean section is performed before 39 weeks, the chance of wet lung in the newborn is higher and the treatment is more difficult. In addition, because of the scar left on the uterus after the first cesarean section, if the uterus is too large, it may cause damage to the original incision scar, resulting in uterine rupture or premature rupture of the membranes. Therefore, if all the indicators are normal, it is recommended to try to insist on cesarean delivery until about 39 weeks. In addition, emergency cases such as premature rupture of membranes and full-term labor may occur during the course of pregnancy up to 39 weeks, which may require an emergency cesarean section for delivery. Therefore, after the first cesarean section, the specific time for the second cesarean section should be chosen according to the condition under the guidance of a professional doctor.