What is the pelvic ultrasound scan with tubal patency looking for?

The tubal patency test or HyCoSy assesses the fallopian tubes, uterus and endometrial cavity. The initial part of the test 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).