Saline Infusion Sonohysterography (SIS)

SIS (also called sonohysterogram or saline sonogram) involves injecting a small amount of sterile saline through the cervix into the uterine cavity while performing a transvaginal ultrasound. The fluid creates contrast that highlights the endometrial lining, making polyps, fibroids, and a uterine septum clearly visible.

It is less invasive than hysteroscopy and does not require general anesthesia, making it ideal as a first-line uterine cavity evaluation before IVF. The procedure takes 15–20 minutes and causes mild cramping similar to a Pap smear.

If an abnormality is found on SIS, diagnostic or operative hysteroscopy is typically performed for confirmation and treatment.