Fertility Treatments: Hysterosalpingogram (HSG) Technique

Hysterosalpingography (HSG) is a radiologic procedure to investigate the shape of the uterine cavity and the shape and patency of the fallopian tubes. It entails the injection of a radio-opaque material into the cervical canal and usually fluoroscopy with image intensification. A normal result shows the filling of the uterine cavity and the bilateral filling of the fallopian tube with the injection material. To demonstrate tubal rupture, spillage of the material into the peritoneal cavity needs to be observed. A synonym to hysterosalpingography is uterosalpingography.

The procedure involves X-rays. It should be done in the follicular phase of the cycle. It is contraindicated in pregnancy. It is useful to diagnose uterine malformations, Asherman's syndrome, tubal occlusion and pelvic inflammatory disease and used extensively in the work-up of infertile women. It has been claimed that the chance of pregnancy increases after HSG has been performed. Using catheters, an interventional radiologist or specifically trained radiographer 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).

The HSG can be painful, so analgesics may be administered before and/or after the procedure to reduce pain. Many doctors will also prescribe an antibiotic prior to the procedure to reduce the risk of an infection.

Complications of the procedure include infection, allergic reactions to the materials used, intravasation of the material, and, if oil-based material is used, embolisation. Air can also be accidentally instilled into the uterine cavity by the operator, thus limiting the exam due to iatrogenically induced filling defects. This can be overcome by administering the Tenzer Tilt, which will demonstrate movement of the air bubbles to the non-dependant portion of the uterine cavity.