Saline Infusion Sonogram (usually shortened to SIS) is a procedure carried out under ultrasound and is used to assess the fallopian tubes, as well as to detect abnormalities of the uterus and endometrium such as endometrial polyps, submucosal fibroids and congenital uterine abnormalities (such as uterine septum).

Blocked fallopian tubes are a common cause of infertility. Blocked tubes can occur with a number of conditions including previous pelvic infection, severe endometriosis, previous appendicitis and pelvic adhesions. Many women will be unaware that these conditions are present and that tubal blockage has occurred. If a tubal blockage is identified your treating doctor will advise on further treatment options. The best time to perform a SIS is just after your period has finished, approximately day 4 to day 12 of a regular 28-day menstrual cycle.