A hysterosonogram or HSN, (also known as sonohysterogram, saline ultrasound, saline sonogram, or saline infusion sonogram) is a minimally invasive ultrasound procedure that can determine if there are abnormalities inside the uterus that might interfere with pregnancy.

  • A Salpingosonogram or Sonosalpingogram is a similar procedure which is extended further to involve the Fallopian tubes to detect tubal pathologies such as tubal blockages that may impair fertility.

It is important to have an evaluation of the uterine cavity with a sonohysterogram before proceeding with an IVF cycle.
This test involves no radiation, and there are very few risks from the procedure as well as least discomfort as compared to the conventional x-ray guided Hysterosalpingography.
Compared to a regular ultrasound, a sonohysterogram is better at detecting abnormalities on the inside walls of the uterus because it involves infusing sterile fluid inside the uterus. This way, the walls of uterus separate from each other and any abnormalities that might have been hiding right along the sides of the walls will be easily identified.
A hysterosonogram/salpingosonogram is often recommended for women who are having:

  • Difficulty conceiving a pregnancy.
  • Recurrent miscarriages
  • Abnormal vaginal bleeding

Since a Hysterosonogram and Salpingosonogram gives such a detailed view of the inside walls of the uterus and the tubal pathologies respectively, both can identify many types of abnormalities that might prevent pregnancy or a normal pregnancy from developing.
Studies have shown that it can detect over 90% of abnormalities inside the uterus. Some of these abnormalities include:

  • Polyps
  • Fibroids
  • Scar tissue and adhesions
  • Uterine abnormalities such as Bicornuate Uterus, uterine septum etc.
  • Tubal blockages
How is a sonohysterogram performed?

The procedure is very simple and usually takes about 5-10 minutes (excluding preparation time).

In order to schedule a sonohysterogram, you will need to call on the first day of your period. You will be given an appointment for some time point after the bleeding from the period has ended but before it is thought that ovulation might occur. This ensures that the uterine lining is as thin as possible. This is important since it will assist the doctor in the visualization of the cavity.

Under sterility, a very thin, soft, flexible plastic catheter will be inserted through the vagina and cervix into the lower part of the uterine cavity.
A vaginal ultrasound probe is then placed into the vagina.
Through the catheter, a small amount of saline (sterile saltwater) is injected into the uterine cavity to separate the walls.

During a sonohysterogram, the ultrasound probe can be rotated to show the various views of the uterus.

This procedure is not painful in the least, unlike the conventional HSG or hysterosalpingogram which is an x-ray procedure with the insertion of dye into your uterus quite painful.

You will be able to watch the sonohysterogram on a monitor while it is being performed. Afterward, the doctor will review the findings with you and answer any questions about those findings.

If there are any abnormalities that are found on the inside of your uterus, don’t worry! Nearly all of these conditions are easily corrected with minimally invasive, outpatient surgery (usually with hysteroscopy).