Infertility bothers many women with tubal blockage or hydrosalpinx. How tubal blockage and hydrosalpinx affect the fertility?

How fallopian tubes work

There are two main function of fallopian tubes:
1 ( The fimbrial end) To grasp the egg which is released by one of the ovaries.
2 The tube wriggles to let the fertilized egg travel to the uterine.

 
How fertilization and pregnancy occur

The fimbrial end is the open, outside end of the fallopian tube. It is composed of delicate "fimbriae" - finger-like projections of the tube lined by cells with cilia. It catches and carry the egg into the ampulla before fertilization.

Ampulla is the most wide part (except for the infundibulum)of the fallopian tube and is where fertilization occurs. The sperm which is ejaculated into the vagina must swim upward the uterine and enter the fallopian tube to "meet" the egg. After egg meets the sperm and fertilization occurs, fertilized egg then travel through the fallopian tube into the uterine and then implant on the endometrium.

How tubal blockage and hydrosalpinx affect the fertility

When tubal blockage or hydrosalpinx develops, the fimbrial end or other part of the tube is adhesive or blocked. If there is a adhesion at the fimbrial end, then the egg cannot be catched and carried into the tube to "meet" the sperm, no fertilization can occur. If the blockage occurs at the ampulla, isthmus or the interstitial, egg cannot pass the ampulla and travel into the uterine. Because tubal blockage and hydrosalpinx are always caused by infection and inflammation, such inflammation may also cause adhesion of connective tissue around the fallopian tube. When those tissues are surrounding and sticked with the tubes, fallopian tubes cannot function well to transport the egg into uterine. Or if the fertilized egg is stucked in the tube, ectopic pregnancy occurs.