When a woman’s Fallopian tubes are obstructed or blocked, the egg and sperm cannot fuse and fertilization does not take place.Tubal obstruction (TO) is the cause of infertility in 25 to 35 % of all female factor infertility cases. It can be a consequence of endometriosis, post-operative adhesions, pelvic inflammatory disease after abortion or infection with sexually transmitted diseases (STDs) such as chlamydia or gonorrhea. As a cause of infertility, TO can be bypassed by in-vitro fertilization techniques (IVF, ICSI), whereby the egg and sperm fuse in vitro rather than in the woman’s body.