Ectopic pregnancy is medically called ectopic pregnancy. The causes of ectopic pregnancy are: 1. tubal inflammation, which is the main cause of ectopic pregnancy, can be divided into tubal mucositis and peri-tubal inflammation. 2. history of tubal surgery, such as tubal ligation, post-tubal ligation recanalization, tubal adhesion release, tubal molding, tubal pregnancy incision and embryo retrieval, etc. 3. tubal dysplasia or functional abnormalities, such as tubal hypertelorism, tubal overgrowth, tubal myometrium 4. Assisted reproductive technology. The rate of ectopic pregnancy due to assisted reproductive technology is clinically observed to be higher than that of natural conception, probably not due to the technology itself, but to the presence of pathogenic factors of infertility in the patients themselves.5. Tubal compression, such as compression of the fallopian tubes by uterine fibroids, ovarian tumors, etc., resulting in narrowing of their lumen.6. Fertilized egg wandering.7. Mental factors. High mental tension and anxiety can cause tubal spasm and abnormal peristalsis. 8. Other factors, such as embryonic defects, abortion, smoking, etc.