Definition and Overview
A hysterosalpingogram is a special type of X-ray used to examine a woman's uterus and fallopian tubes. It is non-invasive although slightly uncomfortable radiologic scan that produces an image of the uterus and fallopian tube to help doctors diagnose existing problems.
Who should undergo and expected results
The procedure is recommended for those who have:
- Abnormalities and malformations in the uterus
- Tubal occlusion
- Pelvic inflammatory disease
- Asherman's syndrome
- Infertility – For women showing signs of infertility, this radiologic exam can be used to diagnose the cause of the problem or, according to some claims, to help increase a woman's chances of conceiving.
Many doctors prescribe this scan when the woman complains of unexplained bleeding not caused by a recent menstrual period.
In some cases, the test is done to confirm that the tubes are indeed blocked, such as when the woman has undergone tubal ligation as a means to prevent pregnancy.
A result that is considered normal is when the uterus and fallopian tube are completely filled by the dye material. This is because when there are no abnormalities or blockages in the fallopian tubes, the dye will spill over. However, if the movement of the dye stops at some point, this may indicate the presence of a blockage. There are two types of blockages that may occur:
- Proximal, or when the blockage is near the tubal junction and the uterus
- Distal, or when the blockage is near the end of the tube
Aside from blockage in the fallopian tubes, an HSG may also detect other abnormalities, such as:
- Developmental and structural defects of the uterus or fallopian tubes
- Scar tissue
- Uterine fibroids
In case some abnormalities are detected, patients may undergo another scan to obtain a delayed image of the uterus and fallopian tubes. This follow-up scan is done either after a rest period of 30 minutes or the following day.
To ensure accurate results, the test should be done approximately 7 to 8 days after the cessation of the patient's menstrual period, i.e. the day the bleeding stops. If the test results are inconclusive, an HSG may be followed by a laparoscopic examination of the uterus, which will give the doctor a 3-dimensional view.
How the procedure works
A hysterosalpingogram is conducted in the radiology department of hospitals, where the patient will be asked to lie on a table under an x-ray machine with her feet held by stirrups. This position is similar to when a woman undergoes a pelvic exam. The whole scan will take approximately 30 minutes, and patients are allowed to return to their regular activities afterwards.
The first part of the procedure is cleaning the cervix before a speculum is inserted into the vagina. This is followed by inserting a catheter into the cervix to inject contrast dye material into the uterus, allowing the substance to flow through the fallopian tubes. The purpose of the dye material is to assist in the imaging process and enhance results, making it easier for doctors to detect abnormal areas in the womb. This is then followed by the actual x-ray scan, which uses a type of radiation that is emitted in waves that pass through the body and instantly captures and records an image. These images are stored in a computer for analysis and review.
An HSG may cause some pain, both at the insertion of the speculum and during the scan, so most patients are given analgesics either before or after the procedure. The pain, during the insertion of the speculum, is like a piercing sensation similar to what is felt during a pap smear, while the sensation during the scan is more similar to menstrual cramping. If there is a blockage in the tubes, the patient will also feel some pain. Some doctors also give antibiotics even prior to the test in order to prevent infections, as well as some medications that will help keep the patient calm and relaxed.
Possible risks and complications
Although generally safe, a hysterosalpingogram has some possible complications, such as:
- Infection, either salpingitis (fallopian tube infection) or endometritis (endometrial infection)
- Allergic response to the contrast dye material
- Embolisation, if an oil-based dye is used
- Intravasation of the dye
- Perforation of the uterus
Post-procedural symptoms that should be reported immediately to the doctor include:
These may indicate the presence of an infection, which need to be treated promptly. However, some light bleeding after the test, lasting for a few days, may be expected as a normal effect of the test.
If the patient has an inflammatory condition or a sexually transmitted infection, it should be treated first before she can undergo the scan. This is to ensure that the scan will not aggravate the existing disease/infection.
Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.