The causes of tubal obstruction are as follows: a. Inflammatory and infectious factors. Inflammation and infection causing tubal inflammation, especially chronic tubal inflammation, is the main cause of tubal obstruction and dysfunction. Infection is often caused by sexual transmission, abortion, etc., which can result in tubal pus accumulation, fluid accumulation and pelvic adhesions, etc.; ii. Endometriosis, ectopic endometrial lesions can cause structural damage to the fallopian tubes and cause tubal blockage. In addition, ectopic endometrial lesions can secrete prostaglandins, which interfere with the rhythmic peristalsis of the fallopian tubes and interfere with the union of sperm and egg, causing infertility; third, congenital abnormalities. Congenital abnormalities in the development of the fallopian tubes, including stage or complete absence of the fallopian tubes, or having fallopian tubes that are too slender, too curly, or without umbilical ends, etc., thus affecting the transport of sperm, eggs or fertilized eggs, and infertility occurs.