A hysterosalpingogram or HSG is often part of the infertility evaluation. It is a test to check the uterine cavity as well as the patency (openness) of the fallopian tubes. The HSG is usually done in the radiology department of a hospital. Radiographic contrast, or dye, is injected into the uterine cavity through the vagina and cervix.

The uterine cavity fills with dye and if the fallopian tubes are open, the dye will then fill the tubes and spill out into the abdominal cavity. The HSG shows whether the fallopian tubes are open or, if they are blocked, where the blockage is located.

The blockage can be distal, at the end of the fallopian tube, or proximal, where the tube meets the uterus. Blockage in each of these two areas has different causes.

There are other things that potentially can be seen on a hysterosalpingogram: The uterine cavity is evaluated for the presence of polyps, fibroid tumors, or scar tissue. The fallopian tubes are also examined for any defects within the tube or suggestion of a partial blockage. Some women are more likely to get pregnant after an HSG.