The study is to compare hysteroscopic repair and transvaginal intervention for correcting uterine defect in patients with post cesarean scar defect (PCSD) and the reproductive prognosis.

Post cesarean scar defect (PCSD), refers the lower uterine segment form a reservoir-like pouch during healing process after transverse lower uterine segment cesarean section connected with uterine cavity. The pouch has a valve-like effect, obstructing blood drainage and accumulating blood in depression. These causes may lead to a variety of gynecological disturbances, secondary dysmenorrheal and infertility. Some patients can occur some serious obstetric complications, such as cesarean scar pregnancy and even the rupture of uterus during a subsequent pregnancy. At present, the causes and mechanisms of PCSD are not clear, diagnosis and treatment are not uniform. Surgical methods include abdominal surgery, laparoscopic surgery, transvaginal surgery, hysteroscopic surgery, hysteroscopic with laparoscopic surgery and so on. Hysteroscopic and transvaginal surgery to treating PCSD both are minimally invasive and feasible surgical approach. However, hysteroscopic surgery and transvaginal surgery have not been compared for correcting the uterine defect in patients with PCSD before.

Inclusion Criteria:

• Patients had a history of transverse lower uterine segment cesarean section;
• Patients had a previous regular menstruation, while after caesarean section, they occurred prolonged postmentrual bleeding (10-20days)
• Medication failed(contraceptive pills).
• Sex hormone test is normal;
• TVU or hysteroscopy showed a triangular or U-shaped anechoic liquid dark area and on the anterior lower uterine segment in relation to cesarean section scar during menstruation of 7-12 days or hysteroscopic examination showed uterine anterior wall defect like dome changes at isthmus below internal orifice of cervix.

Exclusion Criteria:

• Irregular menstrual cycle before cesarean section
• Previous placement of an intrauterine contraceptive device
• Presence of other organic uterine pathology responsible for abnormal uterine bleeding, such as endometrial hyperplasia, polyps or submucosal myomas, cervical cancer, endometrial cancer, etc
• Existence of endocrine diseases, such as dysfunction of pituitary, ovarian, adrenal gland, and thyroid;
• Coagulation dysfunction.

patients who received hysteroscopy in the Department of Obstetrics and Gynecology of the First Affiliated Hospital of Sun Yat-sen University and were diagnosed with post cesarean scar defect according to the transvaginal ultrasonography or hysteroscopy were recruited into present study.