What is a Saline Infusion Sonography (SIS)?

A Sonohysterogram is an ultrasound procedure utilized to evaluate the uterine cavity. The test will determine if uterine abnormalities, such as, fibroids, polyps, scar tissue or uterine malformations, are present. It is routinely performed before In Vitro Fertilization (IVF) to make sure that there are no abnormalities which may interfere with embryo implantation. The test takes only a few minutes to complete and is associated with little discomfort, if any.

During the exam, a speculum (fig. 1) is inserted into the vagina, and an antiseptic solution is utilized to cleanse the vagina and the cervix. A small soft catheter is then inserted through the cervix into the uterus.

A vaginal ultrasound (fig. 2) is then performed. The uterus is seen as a “pear-shaped” structure outlined in blue. The empty uterine cavity is outlined in yellow.

Fig. 2
Fig. 1


The sonohysterogram begins with slow injection of small amount of saline solution into the uterus to determine if there are any uterine abnormalities present.

In a normal sonohysterogram (fig. 3) the uterus, outlined in blue, is slowly filled with saline solution. The dark shaded, fluid filled uterine cavity, is outlined in yellow. There are no “filling defects” within the fluid filled uterine cavity - indicating that the test is completely normal.

When the sonohysterogram is abnormal (fig. 4), a “filling defect” or a fibroid (outlined in red) can be seen within the saline solution filling the uterine cavity (outlined in yellow). Such fibroids or polyps can interfere with fertility and require surgical procedure to remove them.

Fig. 4
Fig. 3


How to schedule the test?

The best time to perform the test is 6-10 days from the beginning of your menstrual cycle. A pregnancy test is performed to make sure you are not pregnant.

What to expect after the test?

After the test you may experience mild cramping similar to that of a menstrual cycle. You may take non steroidal anti-inflammatory medication, such as Motrin, if necessary. You may resume normal activity after the test. Sonohysterogram has not been associated with major complications. Some spotting is expected, but should notify your doctor if you experience heavy bleeding, fever or severe abdominal pain.