Cesarean Section Defect Mechanism and Transvaginal Repair

Inclusion Criteria: 1. Age ≥ 18 years, premenopausal female; 2. The scar is the transverse incision of the lower segment of the uterus (one or more times); 3. The following abnormal uterine bleeding occurred after cesarean section: prolonged menstruation/endless menstruation ≥ 14 days, menstrual bleeding; 4. Transvaginal three-dimensional ultrasound/pelvic MRI plain scan showed that the thickness of residual muscular layer at the top of diverticulum was less than 3 mm; 5. The effect of drug treatment is poor, and it is difficult to adhere to long-term drug treatment or surgical treatment; 6. HGB \> 100g/L before operation; 7. Hysteroscopy excluded endometrial lesions; 8. The patient or family members can understand the study protocol and voluntarily participate in the study, and provide written informed consent. Exclusion Criteria: 1. The data of cesarean section is not complete, and the previous cesarean section method cannot be determined; 2. Abnormal uterine bleeding caused by endocrine disorders (thyroid dysfunction, luteal insufficiency), endometrial lesions, uterine fibroids, gynecological tumors, blood system diseases, pelvic infections, intrauterine devices, etc; 3. Infertility patients caused by female oviduct infertility, intrauterine adhesion infertility, uterine malformation, polycystic ovary syndrome, male infertility, etc; 4. Patients with other serious gynecological diseases and/or serious physical or psychological diseases; 5. Pregnancy (women of childbearing age were positive in pregnancy test at baseline or did not receive pregnancy test), and women in lactation; 6. Patients who are unable to complete the follow-up; 7. The patient or family members could not understand the conditions and objectives of the study and did not agree to participate in the study.