You may have been advised to have this examination due to your medical history along with your test results from Hertility. Causes of tubal occlusion can include previous ectopic pregnancy, previous pelvic infections such as pelvic inflammatory disease (PID), previous appendicitis, pelvic adhesions and severe endometriosis. Occluded (blocked) fallopian tubes are a common cause of infertility. If you are considering trying naturally timed sexual intercourse, ovulation induction or intrauterine insemination (IUI), you will require patent fallopian tubes in order to achieve a pregnancy. The initial part of the tubal patency test or HyCoSy uses saline to assess the uterine cavity for pathology, such as endometrial polyps, submucous fibroids and congenital uterine abnormalities. The next stage is looking to see if either of the fallopian tubes are patent (open and unobstructed).