The main causes of ectopic pregnancy are as follows: 1. tubal inflammation and gynecological inflammation are common causes of tubal pregnancy, tubal inflammation can be divided into tubal mucositis and peri-tubal inflammation. The tubal mucosal inflammation can cause complete obstruction of the tubal lumen, resulting in infertility or adhesion of the tubal mucosa, leading to obstruction of the fertilized egg and its implantation in the fallopian tube to form tubal pregnancy. 2. The incidence of ectopic pregnancy can reach 10%-20%. 3. fertilized egg wandering, as the egg is fertilized in one of the fallopian tubes, the fertilized egg can wander through the uterine or abdominal cavity to the opposite fallopian tube, resulting in ectopic pregnancy. 4. tubal dysplasia or functional abnormalities, such as long fallopian tubes, can also cause ectopic pregnancy. 5. assisted reproductive technology, in vitro fertilization embryo transfer can lead to ectopic pregnancy, with an incidence of about 5%. 6. Other factors, such as abnormal secretion of estrogen and progesterone due to oral contraceptives, can affect the normal transport of fertilized eggs. 7. Psychological factors can also cause spasm or abnormal peristalsis of the fallopian tubes, interfering with the transport of fertilized eggs.