A hysterosalpinogram (HSG) is an X-ray examination to evaluate the shape of the uterus cavity and fallopian tubes. It is normally performed between day 7 and 10 of your menstrual cycle and takes about 30 minutes.

The procedure, generally done in the preovulatory phase of a cycle involves taking X-rays to diagnose uterine malformations, Asherman's syndrome, tubal occlusion and is used extensively to evaluate infertile women. Studies show that pregnancy rates increase in a cycle when an HSG has been performed.

During the test, fluoroscopy is injected into the uterine cavity through the vagina and cervix. If the fallopian tubes are open the contrast agent will fill the tubes and enter the abdominal cavity.

The exam can determine whether the fallopian tubes are open or blocked. If blocked, radiologists can determine whether the blockage is located at the junction of the tube and the uterus (proximal) or whether it is at the end of the fallopian tube (distal).