A hysterosalpingogram (HSG) is an X-ray test that looks at the inside of the uterus and fallopian tubes and the area around them. It often is done for women who are having a hard time becoming pregnant (infertile).
During a hysterosalpingogram, a dye (contrast material) is put through a thin tube that is put through the vagina and into the uterus. Because the uterus and the fallopian tubes are hooked together, the dye will flow into the fallopian tubes. Pictures are taken using a steady beam of X-ray (fluoroscopy) as the dye passes through the uterus and fallopian tubes. The pictures can show problems such as an injury or abnormal structure of the uterus or fallopian tubes, or a blockage that would prevent an egg moving through a fallopian tube to the uterus. A blockage also could prevent sperm from moving into a fallopian tube and joining (fertilizing) an egg. A hysterosalpingogram also may find problems on the inside of the uterus that prevent a fertilized egg from attaching (implanting) to the uterine wall.
Why It Is Done
A hysterosalpingogram is done to:
- Check for a blocked fallopian tube. The test often is done for a woman who is having a hard time becoming pregnant. An infection may cause severe scarring of the fallopian tubes and block the tubes, preventing pregnancy. Occasionally the dye used during a hysterosalpingogram will push through and open a blocked tube.
- Find problems in the uterus, such as an abnormal shape or structure, an injury, polyps, fibroids, adhesions, or a foreign object in the uterus. These types of problems may cause painful menstrual periods or repeated miscarriages.
- See whether surgery to reverse a tubal ligation has been successful.
How To Prepare
Before a hysterosalpingogram, tell your doctor if you:
- Are or might be pregnant.
- Currently have a pelvic infection (pelvic inflammatory disease) or sexually transmitted infection (such as gonorrhea or chlamydia).
- Are allergic to the iodine dye used or any other substance that has iodine. Also tell your doctor if you have asthma, are allergic to any medicines, or have had a serious allergic reaction (anaphylaxis) from any substance (such as the venom from a bee sting or from eating shellfish).
- Have any bleeding problems or are taking any blood-thinning medicines, such as aspirin or warfarin (such as Coumadin).
- Have a history of kidney problems or diabetes, especially if you take metformin (such as Glucophage) to control your diabetes. The dye used during a hysterosalpingogram can cause kidney damage in people with poor kidney function. If you have a history of kidney problems, blood tests (creatinine, blood urea nitrogen) may be done before the hysterosalpingogram to check that your kidneys are working well.
This test should be done 2 to 5 days after your menstrual period has ended to be sure you are not pregnant. It should also be done before you ovulate the next month (unless you are using contraception) to avoid using X-rays during an early pregnancy. You may want to bring along a sanitary napkin to wear after the test because some leakage of the X-ray dye may occur along with slight bleeding.
You may be asked to sign a consent form that says you understand the risks of the test and agree to have it done.
Talk to your doctor about any concerns you have about the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form (What is a PDF document?).
How It Is Done
A hysterosalpingogram usually is done by a radiologist in the X-ray room of a hospital or clinic. A radiology technologist and a nurse may help the doctor. A gynecologist or a doctor who specializes in infertility (reproductive endocrinologist) also may help with the test.
Before the test begins, you may get a sedative or ibuprofen (such as Advil) to help you relax and to relax your uterus so it will not cramp during the test. You will need to take off your clothes below the waist and drape a gown around your waist. You will empty your bladder and then lie on your back on an examination table with your feet raised and supported by stirrups. This allows your doctor to look at your genital area.
Your doctor will put a smooth, curved speculum into your vagina. The speculum gently spreads apart the vaginal walls, allowing him or her to see the inside of the vagina and the cervix. The cervix may be held in place with a clamp called a tenaculum. The cervix is washed with a special soap and a stiff tube (cannula) or a flexible tube (catheter) is put through the cervix into the uterus. The X-ray dye is put through the tube. If the fallopian tubes are open, the dye will flow through them and spill into the belly where it will be absorbed naturally by the body. If a fallopian tube is blocked, the dye will not pass through. The X-ray pictures are shown on a TV monitor during the test. If another view is needed, the examination table may be tilted or you may be asked to change position.
After the test, the cannula or catheter and speculum are removed. This test usually takes 15 to 30 minutes.
How It Feels
You probably will feel some cramping like menstrual cramps during the test. The amount of pain you have depends on what problems the doctor finds and treats during the test.
There is always a small chance of damage to cells or tissue from being exposed to any radiation, including the low levels of radiation used for this test. The chance of damage from the X-rays is generally very low compared with the potential benefits of the test.
There is a small chance of a pelvic infection, endometritis, or salpingitis after the test. The chance may be higher for women who have had pelvic infections before. Your doctor may give you antibiotics if he or she thinks you might develop a pelvic infection.
There is a small chance of damaging or puncturing the uterus or fallopian tubes during the test.
There is a small chance of an allergic reaction to the iodine X-ray dye, especially if you are allergic to any shellfish.
In rare cases, if an oil-based dye is used, the oil can leak into the blood. This can cause blockage of blood flow to a section of the lung (pulmonary embolism). Most hysterosalpingogram tests use water-based dyes.
After the test
After the test, some of the dye will leak out of the vagina. You also may have some vaginal bleeding for several days after the test. Call your doctor immediately if you have:
- Heavy vaginal bleeding (soak more than one tampon or pad in one hour).
- A fever.
- Severe belly pain.
- Vaginal bleeding that lasts for more than 3 to 4 days.
The shape of the uterus and fallopian tubes are normal. The fallopian tubes are not scarred or damaged. The dye flows freely from the uterus, through the fallopian tubes, and spills normally into the belly.
No objects (such as an intrauterine device, or IUD), tumors, or growths are seen in the uterus.
Fallopian tubes may be scarred, malformed, or blocked so that the dye does not flow through the tubes and spill into the belly. Possible causes of blocked fallopian tubes include pelvic inflammatory disease (PID) or endometriosis.
The dye may leak through the wall of the uterus, showing a tear or hole in the uterus.
An abnormal uterus may show tissue (called a septum) that divides the uterus.
What Affects the Test
Reasons you may not be able to have the test or why the results may not be helpful include:
- If your fallopian tube has a spasm. This may make a normal fallopian tube look blocked.
- If the doctor can't put a catheter in the uterus.
This test is not done on women who are having their period, are pregnant, or have a pelvic infection.
What To Think About
- In some cases, a pelvic ultrasound test may be done instead of a hysterosalpingogram to find foreign objects in the uterus, such as an intrauterine device (IUD). To learn more, see the topic Pelvic Ultrasound.
- Some early tests to find the cause of infertility may include tests such as semen analysis and blood tests for luteinizing hormone (LH), progesterone, or follicle-stimulating hormone (FSH). If these tests can't find the cause of infertility, a hysterosalpingogram may be done. To learn more, see the topic Infertility Testing.
- A hysterosalpingogram is done mainly for women who are having a hard time becoming pregnant. Some studies show that this test may help a woman's chance of becoming pregnant because the dye may remove mucus plugs, straighten the fallopian tubes, and break through thin scar tissue.
- Hysteroscopy may be done instead of a hysterosalpingogram to look at the uterus. Another test called laparoscopy may also be done instead of a hysterosalpingogram to look at the fallopian tubes. A laparoscopy does not show whether the fallopian tubes are open, unless dye is injected during the laparoscopy.
- Another test, a sonohysterogram (SHG), may be more accurate than a hysterosalpingogram for looking at uterine fibroids or polyps. SHG uses ultrasound to watch the movement of a salt solution (saline) that is injected into the uterus. SHG does not use X-rays or an iodine dye.
- If a blocked fallopian tube is the cause of infertility, an oil-based dye may be used during a hysterosalpingogram to remove the blockage. Some studies show that an oil-based dye may open up a blockage better than a water-based dye, but other studies have shown no difference between the two dyes.
- Be sure your doctor knows if you take metformin (such as Glucophage) for diabetes or for any other reason, such as polycystic ovary syndrome (PCOS), because of the possible interaction with the dye used in this test.
Other Works Consulted
- 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.
|Sarah Marshall, MD - Family Medicine|
|Deborah A. Penava, BA, MD, FRCSC, MPH - Obstetrics and Gynecology|
|Last Revised||August 1, 2012|
Last Revised: August 1, 2012
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