What to Expect During an HSG (Hysterosalpingogram)

Why an HSG Is Done + What the Procedure Involves + Possible Risks

Surgeon looking at X-ray film in hospital, an HSG x-ray is a female fertility test
An HSG is a special kind of x-ray that can help diagnosis some causes of infertility.. Aping Vision / STS/Taxi/Getty Images

A hysterosalpingogram (HSG) is a special kind of x-ray used to evaluate female fertility. An HSG is an outpatient procedure. The test takes no longer than a half hour. It involves placing an iodine-based dye through the cervix and taking x-rays. These x-rays help evaluate the shape of the uterus and whether the fallopian tubes are blocked.

Hysterosalpingogram is pronounced /he-ster-o-sal-ping-o-gram/.

Luckily, almost no one calls it by the full name. They just say HSG.

If you've been having trouble conceiving, an HSG is one of the first fertility tests that may be ordered. If you've had two or more miscarriages, an HSG is also recommended.

Preparing for Your HSG

An HSG should be done after your period but before ovulation. This is to reduce the risk of having the test when you're pregnant. 

Your fertility clinic or doctor will tell you when to call to schedule the test. Usually, it'll be somewhere between day 10 and 12 of your menstrual cycle. 

The HSG is performed while you are awake and does not involve general anesthesia. You won't need to fast the day or night before. 

On the day of the test, your doctor may suggest taking a pain-killer like ibuprofen an hour before your HSG is scheduled.

This can help with the discomfort of the test.

Also, some doctors prescribe antibiotics to reduce the risk of infection.

The HSG Procedure: What to Expect

Before the test, you'll be asked to remove your pants and/or underwear. You'll put on a gown.

For the test, you'll lie down on an examination table. The table will probably have stir-ups, like the ones found in a gynecologist's office.

The doctor will perform a quick pelvic exam.

 He will place a speculum inside your vagina like they do for a pap smear.

Then, the doctor will place a device called a cannula into your cervix. This is a thin catheter-like tube. You may have some pain or cramping.

Over the exam table will be an x-ray machine. The doctor will move the x-ray down and over the pelvic area before proceeding. 

Next, the doctor will inject an iodine-based dye through the cannula. 

This dye will go through your uterus, through the fallopian tubes (if they are open), and spill out into the pelvic cavity. It may feel warm.

If your tubes are blocked, you experience pain. Tell your doctor right away if you do. 

After injecting the dye, your doctor will take the x-rays.

For each x-ray picture, you'll be asked to hold your breath for a moment or two.

You may be asked to change your position. For example, he may ask you to lie on your side. This can be really awkward with the speculum inside and the x-ray over you. Your doctor understands. Ask for help if you need it.

Once the doctor has decided that the pictures are satisfactory, the x-ray machine will be lifted up. The speculum removed.

You're free to go home!

What are the Risks of an HSG?

Generally, an HSG is a safe procedure. Still, there are potential risks.

Infection may occur in less than 1% of cases. This is more common if you've already had an infection or you're at risk for pelvic inflammatory disease (PID.) 

If you experience fever or increasing pain after the test, call your doctor.

Another risk is fainting during or after the test. If you feel dizzy after the exam, tell your doctor. It may be better for you to remain lying down until you feel less woozy.

A rare but potentially serious risk is iodine allergy.

If you are allergic to iodine or shellfish, tell your doctor before the test. If you have any itching or swelling after the test, tell your doctor.

Is the Radiation from an HSG Safe?

Usually, when you have an x-ray, the first thing the technician does is cover your pelvic area. During an HSG, the x-ray is aimed right at the pelvis.

It's normal to be worried about this.

Be reassured, however, that an HSG involves a very low amount of radiation.

HSG radiation has not been found to cause any unwanted effects, even if you get pregnant later that cycle.

However, an HSG should not be done during pregnancy.

If you think you may be pregnant, tell your doctor before you have the test.

How Will I Feel After the Test?

You may experience mild cramps and light spotting. Over-the-counter pain relievers should help with cramps.

(See this article on HSG and pain for more information.)

Generally, you'll be able to resume normal activity after the test.

Some doctors may tell you to refrain from sexual intercourse for a few days after the test.

What Do the Results Mean?

The HSG helps the doctor check out two important factors:

Whether or not the fallopian tubes are blocked or open. If the fallopian tubes are blocked, a woman will not be able to get pregnant, because the egg can't meet the sperm.

You can read more about diagnosis, causes, and treatment for blocked fallopian tubes here:

Whether or not the shape of the uterus is normal. In 10% to 15% of women with recurrent pregnancy loss, an abnormally shaped uterus is to blame.

Some uterine abnormalities can be treated with surgery. You can read more about the connection between uterine shape and miscarriage here:

If the x-ray shows a normal uterine shape, and the injected dye spills freely out from the ends of the fallopian tube, then the test results are considered normal. 

This doesn't, however, mean your fertility is normal. It just means whatever may be wrong wasn't seen on the HSG.

Hormonal-based causes of infertility will not be seen on an HSG. Not all uterine based fertility problems can be visualized with an HSG. 

One small study found a 35% incident of false negatives with an HSG.

In other words, the HSG showed a normal uterine shape, but a hysteroscopy showed abnormalities. (Hysteroscopy involves placing a thin, telescope-like camera through the cervix to look at the inside of the uterus.)

Also, endometriosis can't be diagnosed with an HSG. Only an exploratory laparoscopy can rule-out or diagnose endometriosis. 

What Happens If the Results Are Abnormal?

If the dye shows an abnormally shaped uterus, or if the dye does not flow freely from the fallopian tubes, there may be a problem.

It's important to know that 15% of women have a "false positive." This is when the dye doesn't get past the uterus and into the tubes. The blockage appears to be right where the fallopian tube and uterus meet.

If this happens, the doctor may repeat the test another time or order a different test to confirm. 

An HSG can show that the tubes are blocked, but it can't explain why.

Your doctor may order further testing, including exploratory laparoscopy or a hysteroscopy. These procedures can both help investigate the issue and possibly correct the problem.

More on causes of infertility:

More about fertility testing and infertility:

Sources:

Hysterosalpingogram (HSG): Patient Fact Sheet. American Society of Reproductive Medicine. Accessed November 13, 2008. https://www.asrm.org/uploadedFiles/ASRM_Content/Resources/Patient_Resources/Fact_Sheets_and_Info_Booklets/hsg.pdf

Recurrent Pregnancy Loss: Patient Fact Sheet. American Society of Reproductive Medicine. Accessed November 13, 2008. https://www.asrm.org/uploadedFiles/ASRM_Content/Resources/Patient_Resources/Fact_Sheets_and_Info_Booklets/recurrent_preg_loss.pdf

Wang CW, Lee CL, Lai YM, Tsai CC, Chang MY, Soong YK. "Comparison of hysterosalpingography and hysteroscopy in female infertility." The Journal of the American Association of Gynecologic Laparoscopists. 1996 Aug; 3(4):581

Continue Reading