Hysterosalpingogram:
A hysterosalpingogram (HSG) is an X-ray test that examines the inside of uterus and fallopian tubes and the surrounding area. It often is done for women who are unable to become pregnant (infertile).
During a hysterosalpingogram, a dye called contrast material is injected through a thin tube that is inserted through the vagina into the uterus. Because the uterus and the fallopian tubes are connected, the contrast material will flow into the fallopian tubes. As the contrast material passes through the uterus and fallopian tubes, continuous X-ray pictures are taken. The pictures can reveal problems such as an injury or abnormal structure of the uterus or fallopian tubes, or blockage that would prevent an egg passing through a fallopian tube from reaching the uterus. Blockage also could prevent sperm from traveling into a fallopian tube and fertilizing an egg. A hysterosalpingogram also may detect abnormalities on the inside of the uterus that might prevent a fertilized egg from attaching (implanting) to the uterine wall. See an illustration of a hysterosalpingogram (http://www.webmd.com/hw-popup/Hysterosalpingogram-of-uterus).
Why It Is Done
A hysterosalpingogram is done to:
Detect a blocked fallopian tube. The test often is done for a woman who is having difficulty becoming pregnant. An infection that causes severe scarring of the fallopian tubes can block the tubes, preventing pregnancy. Occasionally a hysterosalpingogram will open a blocked tube.
Identify problems of 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.
Determine whether surgery to reverse a tubal ligation has been successful.
Determine the success of a tubal ligation, if there is a question about the success of this surgery. However, this is rare.
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 disease (such as gonorrhea or chlamydia).
Are allergic to the iodine dye used in the contrast material or any other substance that contains iodine. Also tell your doctor if you have asthma, are allergic to any medications, or have ever 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 medications, such as aspirin or warfarin (Coumadin).
Have a history of kidney problems or diabetes, especially if you take metformin (Glucophage) to control your diabetes. The contrast material 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 functioning properly.
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 (unless you are using contraception) to avoid the possibility of 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 contrast material may occur along with slight bleeding.
You may need to sign a consent form that says you understand the risks of a hysterosalpingogram and agree to have the test done. Talk to your health professional about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will indicate. 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. The doctor may be assisted by a radiology technologist and a nurse. A gynecologist or a doctor who specializes in infertility (reproductive endocrinologist) also may help with the test.
Before the test begins, you may be offered a sedative or ibuprofen (such as Advil) to help you relax and to reduce the chance of uterine cramping. You will need to take off your clothes below the waist and drape a paper or cloth covering 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 easily examine your vagina and surrounding area.
An X-ray may be taken to ensure that there is nothing in the large intestine (colon) that could block the view of the uterus and fallopian tubes. Sometimes a laxative or enema is given a few hours before the procedure to empty the large intestine.
Your doctor will insert an instrument with smooth, curved blades (speculum) into your vagina. The speculum gently spreads apart the vaginal walls, allowing the inside of the vagina and the cervix to be seen. The cervix may be grasped and held in place with a clamp (called a tenaculum). The cervix is then cleaned and a stiff tube (cannula) or a flexible tube (catheter) is inserted through the cervix into the uterus. The X-ray contrast material, which may be either a water-soluble or oil-soluble dye, is injected through the tube. If the fallopian tubes are normal, the contrast material will flow through them and spill into the abdominal cavity where it will be absorbed naturally by the body. If a fallopian tube is blocked by scar tissue, the contrast material will not pass through. The X-ray pictures are viewed on a video monitor during the test. If a view from the side is needed, the examination table may be tilted or you may be asked to change position.
After the test, the cannula or catheter is removed. This test usually takes 15 to 30 minutes.
You may need to have another pelvic X-ray taken the next day.
Avoid douching or sexual intercourse for 2 weeks after the test to reduce the risk of infection.
How It Feels
You probably will feel some cramping similar to menstrual cramps during the test. The amount and length of the discomfort depends upon the condition of the fallopian tubes, the type of contrast material used, and the pressure used for injecting the contrast material. Contrast material injected at high pressure into a blocked tube can produce severe pain that can last for several hours. Abdominal or pelvic discomfort can be greater after the procedure if oil-based contrast material was used instead of water-soluble contrast.
Risks
There is always a slight risk of damage to cells or tissue from being exposed to any radiation, including the low levels of radiation used for this test. However, the risk of damage from the X-rays is usually very low compared with the potential benefits of the test. There are precautions you can take to reduce your risk of radiation exposure from X-rays.
There is some risk (less than 1 in 100) of a pelvic infection, endometritis, or salpingitis following this test. The risk may be higher for women who have had previous pelvic infections. Your health professional may prescribe antibiotics if he or she considers you at risk for a pelvic infection.
There is some risk of damaging or puncturing the uterus or fallopian tubes.
The use of oil-soluble contrast material has a very slight risk of introducing oil droplets into the bloodstream. This can cause blockage of blood flow to a section of the lung (pulmonary embolism), a very serious condition. Most diagnostic hysterosalpingogram tests are performed with water-soluble contrast material.
After the test
After the test, some of the contrast material will leak out of the vagina. You also may have slight vaginal bleeding for several days after the test. Contact your doctor immediately if you notice:
Heavy vaginal bleeding (more than one tampon or menstrual pad per hour).
A fever.
Severe abdominal pain.
Vaginal bleeding that continues for more than 3 to 4 days.
Results
Hysterosalpingogram Normal:
The shape of the uterus and fallopian tubes are normal. The fallopian tubes are not scarred or damaged. The contrast material does not leak out of the uterus, flows freely through the fallopian tubes, and spills into the abdomen. No objects (such as an intrauterine device, IUD), tumors, or abnormal growths can be seen in the uterus.
Abnormal:
Fallopian tubes may be scarred, malformed, or blocked so that the contrast material does not flow smoothly through the tubes and out into the abdomen. Possible causes of blocked fallopian tubes include pelvic inflammatory disease (PID) or endometriosis. The contrast material may leak through the wall of the uterus, indicating a tear or hole in the uterus. An abnormal uterine cavity may reveal tissue (called a septum) that divides the uterus. Abnormal growths (such as polyps or fibroids) may be present.
What Affects the Test
Factors that can interfere with your test and the accuracy of the results include:
A spasm of a fallopian tube, which may make a normal fallopian tube appear blocked.
In rare cases, stool (feces) or gas in the large intestine (colon).
This test should not be done on women who are menstruating, 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 detect foreign objects in the uterus (such as an intrauterine device, or IUD). For more information, see the medical test Pelvic Ultrasound.
Initial testing to determine 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 cannot determine the cause of infertility, a hysterosalpingogram may be done. For more information, see the medical test Infertility Testing.
A hysterosalpingogram is done mainly for women who are having difficulty becoming pregnant. Some studies suggest that this test may actually increase a woman’s chance of becoming pregnant. This may be because injection of the contrast material may remove mucous plugs, straighten the fallopian tubes, and break through thin scar tissue.
Hysteroscopy may be done used instead of a hysterosalpingogram to examine the uterus. Another test called laparoscopy may be done instead of a hysterosalpingogram to view the fallopian tubes. Unlike a hysterosalpingogram, laparoscopy does not show whether the fallopian tubes are open, unless contrast material is injected during the laparoscopy. For more information, see the medical test Laparoscopy.
Another test, a sonohysterogram (SHG), is more accurate than a hysterosalpingogram for evaluating uterine fibroids or polyps. SHG uses ultrasound to monitor the movement of a salt solution (saline) that is injected into the uterus. SHG does not use X-rays or an iodine-containing dye.
If a blocked fallopian tube is suspected of causing infertility, an oil-soluble contrast material may be used during a hysterosalpingogram to increase the chance of removing the blockage. Some studies have shown that the use of oil-soluble contrast material during a hysterosalpingogram has a higher rate of improving fertility than water-soluble contrast. However, other studies have shown no difference in fertility rates.
Be sure your doctor knows if you take metformin (Glucophage) for diabetes or for any other reason (such as polycystic ovary syndrome [PCOS]) because of the contrast material used in this test.
Author Jan Nissl, RN, BS
Editor Susan Van Houten, RN, BSN, MBA
Associate Editor Tracy Landauer
Primary Medical Reviewer Renée M. Crichlow, MD - Family Medicine
Specialist Medical Reviewer R. Hugh Gorwill, MD - Obstetrics and Gynecology