Saline infusion sonography (SIS) involves gently instilling sterile saline into the uterine cavity through a thin catheter while performing a transvaginal ultrasound. The fluid separates the walls of the uterus, making it easier to see polyps, fibroids, adhesions or an irregular cavity shape than with a standard scan. SIS is generally quick, done without anaesthesia, and is often used before embryo transfer or IUI to confirm the uterine cavity is normal, or as an alternative to HSG for assessing cavity shape, though it gives less information about whether the fallopian tubes are open.
Also known as: SIS, sonohysterography
Related India guides
Sources
- ICMR Standard Treatment Workflows (icmr.gov.in/standard-treatment-workflows-stws)
- Federation of Obstetric and Gynaecological Societies of India (fogsi.org)
Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.