Role of Chronic Endometritis in Postoperative Recurrence of Severe Intrauterine Adhesions

Inclusion Criteria: * Pre-operative adhesion score was ≥5 * The prior menstrual cycle was regular, and the sex hormone was normal * with informed consent * absence of other uterine abnormality at transvaginal ultrasound * There were no severe systemic diseases, and no contradictions to aspirin, estrogen and surgery. Exclusion Criteria: * Pre-operative adhesion score was \<5 * Prior menstrual cycle was irregular and sex hormone was abnormal, or patients had endocrine factors that caused amenorrhea, menstrual reduction and infertility * other uterine abnormality at transvaginal ultrasound * without informed consent * Patients had contradictions to estrogen and aspirin such as cancers (breast cancer and endometrial cancer), thrombotic diseases, allergy to antipyretic analgesics, severe liver injury, hypoprothrombinemia, vitamin K deficiency, hemophilia, thrombocytopenia, gastric or duodenal ulcer and asthma * refuse Endometrial biopsy * Vaginal discharge abnormal, or Suspected vaginitis or pelvic inflammatory disease, or using antibiotics.