Normal Fallopian Tube Function
The fallopian tubes allow the egg to travel from the ovaries to the uterus and measure 8-10 cm long (4-6 inches). After the oocyte is released from the ovary, the fimbria or finger-like ends of the fallopian tube capture the egg and tiny hair-like cillia lining the tubes wave the egg toward the uterus. Cells lining the tube secrete substances that nourish the egg during its progress. If conditions are right, a sperm may fertilize the egg in the portion of the tube far from the uterus. The fertilized egg, now an embryo, is propelled toward the uterus by muscular contractions of the tube, and the waving cillia, on a journey that takes almost a week. If the delicate tubes have been damaged at any point, the process described above may be interrupted, and pregnancy may occur in the tube (ectopic pregnancy) or may not be able to occur at all.
Tubal Factor Infertility
Tubal factor infertility can occur for many reasons.
If a woman has Endometriosis, endometrial tissue called implants can attach to the tube and can grow and bleed each month just like uterine endometrial tissue does. As the cells grow, the tissue can penetrate the tubes which causes damage, or it can cause scarring of the tubes which can cause blockages.
Pelvic Inflammatory Disease (PID) is caused most commonly by Chlamydia and Gonorrhea, but any serious infection in the pelvis may cause scarring of the tubes and damage to other reproductive organs as well.
Surgery in the pelvis can lead to the formation of scar tissue. If scar tissue forms near, around or within the fallopian tubes, it can cause blockages. Some woman have had intentionally had tubal surgery for birth control called a tubal ligation.
In some rare cases, a birth defect causes a woman to be born with one or no fallopian tubes.
Hydrosalpinx is a condition meaning literally ‘water in the tube’. The tube was damaged and filled with fluid, causing the tube to dilate and lose function. This fluid is toxic to embryos, so your doctor may recommend to you to have your damaged tube(s) removed before proceeding with IVF or other fertility treatments.