The procedure involves ionizating x-rays and should be done in the preovulatory phase of the cycle; it is contraindicated in pregnancy. It is useful to diagnose uterine malformations, Asherman's syndrome, tubal occlusion and used extensively in the work-up of infertile women. It has been claimed that pregnancy rates are increased in a cycle when an HSG has been performed. Using catheters, an interventional radiologist can open tubes that are proximally occluded.
The test is usually done with radiographic contrast medium (dye) injected into the uterine cavity through the vagina and cervix. If the fallopian tubes are open the contrast medium will fill the tubes and spill out into the abdominal cavity. It can be determined whether the fallopian tubes are open or blocked and 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).
For the first HSG Carey used collergol in 1914. Lipiodol was introduced by Sicard and Forestier in 1924 and remained a popular contrast medium for many decades. Later, water-soluble contrast material was generally preferred as it avoided the possible complication of oil embolism.