A sonohysterogram or SHG is a saline ultrasound, saline sonogram, or saline infusion sonogram. A sonohysterogram is a minimally invasive ultrasound procedure that can determine if there are abnormalities inside the uterus that might interfere with pregnancy. It is important to have an evaluation of the uterine cavity with a sonohysterogram or other method before proceeding with an IVF cycle. This test involves no radiation, and there are very few risks from the procedure. 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.
Here is an example to help understand why we do a sonohysterogram. Think of your uterus like a collapsed balloon. If there was a small growth or bump on the inside wall of the collapsed balloon, it might be hard to see since the top and bottom walls are touching each other. However, if we inflated the balloon, the small growth will be easier to see since it will likely be able to hang away from the wall.
Traditionally, the “best” way to look for abnormalities inside the uterus was a test called a hysteroscopy, which involves an out-patient surgery using a type of endoscope to look inside the uterus. However, in recent years, the techniques for a sonohysterogram have become so advanced that it has usually replaced hysteroscopy as the first procedure to look for abnormalities in the uterus. Compared to a hysteroscopy, a sonohysterogram is less invasive, less expensive and nearly as effective at detecting abnormalities.
