According to the ACOG guidelines for vaginal delivery after cesarean section, the indications for vaginal delivery in patients with scarred uterus are as follows: 1. The previous cesarean section was a transverse incision of the lower uterus. No intraoperative incisional tear, good postoperative incisional healing and no infection. 2. The pregnancy is 2 years or more from the previous cesarean section. 3. Ultrasound showed that the thickness of the anterior wall scar of the lower uterine segment was more than 2-4 mm and there was no weak area. 4. No history of uterine scarring or uterine rupture such as myomectomy or hysteroscopic electrosurgery. 5. The fetal size was evaluated by ultrasound before vaginal trial of labor and the fetal weight was less than 4000 g. 6. The previous indication for cesarean delivery no longer existed and no new indication for cesarean delivery appeared. 7. No serious complications of pregnancy and no other medical or surgical complications that are not suitable for vaginal delivery. 8. The labor progressed smoothly during the trial of labor; the pregnancy was eligible for vaginal delivery and there were no abnormalities in the three elements of labor; the intrapelvic measurements were normal. 9. The fetus is stillborn in utero or has serious malformations. 10, there is better medical monitoring equipment, physicians can be present at any time to monitor the delivery, can immediately anesthesia, emergency cesarean section staff can be present at any time, with the conditions of surgery, blood transfusion and resuscitation.