Tubal factor infertility occurs when a blockage within the fallopian tubes won't allow the egg and sperm to satisfy. Tubal factor infertility accounts for about 25-30% of all cases of infertility. The condition includes cases of completely blocked fallopian tubes and cases where only one is blocked tube or scarring narrows the tubes.Infections, abdominal surgery, and diseases like endometriosis can cause scarring between the top of the Fallopian tube and ovary. Infections could also be, but aren't necessarily, sexually transmitted. Chlamydia and gonorrhea are two common sexually transmitted infections which will cause tubal infertility. Tuberculosis, uncommon in North America, and a ruptured appendix can both cause a tubal infection. Surgery also can damage your fallopian tubes. Pelvic disease (PID) also can travel from the cervix through the uterus to the tubes, which may ultimately cause the fragile inner lining of the tubes to become permanently scarred. The opening of the tube next to the ovary may become partially or completely blocked; connective tissue will often form on the surface of the tubes and uterus