Causes of ectopic pregnancy in the fallopian tube

The most common site of ectopic pregnancy is the fallopian tube, accounting for 95% of all cases. Tubal pregnancy is associated with the following factors:

Fallopian tube inflammation

The lining of the fallopian tube forms a narrow part due to inflammation, the fallopian tube is tortuous or there is inflammation and adhesion around the fallopian tube, which often blocks the fertilized egg. Salpingitis not only causes changes in the morphology of the fallopian tube, but also often causes defects in the cilia of the fallopian tube lining, reduces the peristaltic ability of the fallopian tube, affects the migration of the fertilized egg, and leads to tubal pregnancy.

Fallopian tube malformations

In cases of dysplastic fallopian tubes, the muscle fibers of the fallopian tube wall are poorly developed or absent, the cilia of the inner membrane are absent, the shape is thinner than normal fallopian tubes, and the fallopian tubes are curved and spiral, and longer than normal. In cases of malformation, there are multiple holes, diverticula, double fallopian tube openings, or an additional dysplastic fallopian tube, which is an accessory fallopian tube, and fallopian tube pregnancy is more likely to occur.

Endometriosis

Endometrial tissue can invade the interstitial part of the fallopian tube, causing the interstitial part to thicken, and the lumen to narrow or block, which is one of the causes of tubal pregnancy. Some people have suggested that the endometrium ectopically located in the fallopian tube, ovary, and pelvic cavity may have some chemotactic effect on the fertilized egg, inducing the fertilized egg to implant in the fallopian tube.

Pelvic tumor

Compression or traction from pelvic tumors can cause the fallopian tubes to become thinner and longer, making them tortuous, hindering the passage of the fertilized egg and leading to tubal pregnancy.

Chlamydia infection

Chlamydia infection is an independent important factor for tubal pregnancy. When the chlamydia antibody titer is 1:16, the relative risk is 2.91; when the chlamydia antibody titer is 1:64, the risk is 3.0.