Any factor that causes destruction of the uterine lining can cause uterine cavity adhesion, uterine cavity adhesion related to pregnancy in about 9l%; common in the abortion or spontaneous abortion after scraping. As well as postpartum hemorrhage after scraping. Due to the soft wall of the pregnant uterus, it is not easy to control the depth of scraping, or excessive scratching of the uterine cavity, suction pressure is too large, too long. Scrape off the endometrial basal layer, resulting in postoperative uterine adhesions; suction head, spatula repeatedly in and out of the uterine orifice, irregular dilatation of the cervix, etc. can exacerbate the damage and increase the chance of postoperative uterine adhesions; non-pregnancy-induced uterine adhesions accounted for about 9%, such as endometrial tuberculosis, fibroid removal, diagnostic scraping, and so on. 1, the history of uterine operation (1) pregnancy factors: pregnancy-related uterine surgery such as early pregnancy negative pressure suction, mid-pregnancy pincer scraping, mid-pregnancy induced abortion scraping, postpartum hemorrhage scraping and spontaneous abortion scraping. This may be due to the fact that the endometrial basal layer of the pregnant uterus is more susceptible to damage, which in turn causes the uterine walls to adhere to each other and form permanent adhesions. (2) Non-pregnancy factors: fibroid enucleation (into the uterine cavity), uterine submucosal fibroid removal through the uterine cavity, longitudinal resection of the uterus, double uterus orthopedic surgery, etc. destroyed the basal layer of the endometrium, so that the myometrium is exposed to the uterine cavity, resulting in the front and back of the wall of the uterus adhesions. 2.Surgical inflammatory factors Intrauterine infection of uterine tuberculosis, postmenopausal endometritis in old age, secondary infection after operation of the uterine cavity, puerperal infection, secondary infection caused by placing intrauterine device after operation, and so on. 3, artificial factors artificially destroy the endometrial basal layer, so that the uterine cavity adhesions. For example, after endometrial electrolysis, microwave, freezing, chemical treatment and local radiation therapy in the uterine cavity. 4, due to various reasons scraping endometrial damage, such as repeated scraping, which is very easy to damage the basal layer, caused by this cause of the uterine cavity adhesion is called injury adhesion, for the most common, therefore, obstetricians and gynecologists in the scraping of the depth to be moderate, women of childbearing age to implement good contraceptive measures to avoid abortion, especially the first abortion may result in the uterine cavity adhesion secondary infertility in the future.