HSG (Tubal X-ray)

HSG (hysterosalpingography, the "uterine X-ray") is a diagnostic method in which a contrast material given through the cervix is followed on X-ray to show the shape of your uterine cavity and whether your fallopian tubes are open. Its purpose is to image a problem; it is not a procedure planned to treat anything. The information below offers a general framework and does not replace a diagnosis or treatment recommendation specific to you.

What is HSG (hysterosalpingography), and what is it requested for?

Hysterosalpingography (HSG) is an examination that makes your uterine cavity and tubes visible under X-ray. These spaces, normally not visible on X-ray, become distinct with the contrast material given into them. It seeks to answer two basic questions: is the shape of your uterine cavity regular, and can the contrast material pass through the tubes into the abdominal cavity?

According to current guidelines, HSG and contrast ultrasound are valid methods for assessing tubal patency; in deciding which to use, accessibility, trained staff and the possibility of allergy are taken into account. The two methods are regarded as comparable, and the choice depends on your doctor's preference and yours. Your doctor decides which method is suitable for you.

In which situations is HSG requested, and in which is it not done?

HSG is most often considered in the assessment of couples having difficulty conceiving. Apart from this, a previous ectopic pregnancy or suspected tubal damage, a previous pelvic infection, recurrent pregnancy loss and suspected abnormality in the shape of the uterine cavity are also among the reasons. If you are at high risk of tubal blockage, showing your tubes by imaging is good practice; this risk is not the same in everyone, and the test is requested by looking at your history and your other results.

HSG is not done when there is a possibility that you are pregnant, because exposure to X-rays is involved. It is also postponed if you have signs of an active pelvic infection. If you have a history of allergy to the contrast material or to latex, you need to tell your doctor before the procedure; in this case a different method may be chosen for you.

How do you prepare for HSG, and how is the timing determined?

Because X-rays are used in HSG, your appointment date is arranged for the period when the possibility of pregnancy is low: mostly after your period has finished, before ovulation. If the planned day is not suitable because of bleeding, your doctor moves the date.

Your preparation varies with your doctor's standard. In general, the following subjects are discussed:

• The possibility of pregnancy and the date of your last period
• Your allergies to contrast material, latex, medicines or anything else
• Any pelvic infection or operations you have had before
• Whether a painkiller is needed before the procedure, and any additional preparation considered necessary

Your doctor determines the preparation you need, including medicine and dose, according to you.

What happens during the procedure?

The procedure is done in a room containing the X-ray machine, with you lying on your back on the table. While the contrast material is slowly given through a thin catheter placed in your cervix, the images are watched on the screen and recorded. The contrast first filling your uterine cavity, then your tubes, and spreading into the abdominal cavity suggests that the tubes are open. You may be asked to change position during imaging. You generally go home the same day; the details vary with the practice.

Is HSG painful?

Pain varies a great deal from person to person. Many people feel a cramp similar to period pain; discomfort may increase while the catheter is placed and the contrast is given. During the procedure, while you are with the health staff, a brief spell of dizziness may occur and can be regarded as usual. A painkiller may be suggested to you before the procedure to reduce the pain; relaxation and breathing techniques may also help. If the pain becomes unbearable, tell the person performing the procedure.

Which symptoms are usual after the procedure?

After the procedure you may see mild cramp and light spotting; these are expected complaints and lessen in a short time. If you notice fever, pain that gets progressively worse and foul-smelling discharge together, this may be a sign of pelvic infection. Your doctor will tell you when you can return to daily activities and sexual intercourse.

What are the risks and limits of HSG?

HSG is a widely used procedure, but it cannot be said to have no risks. The main problems are as follows:

• Pain and cramp; a feeling of dizziness
• Light bleeding or spotting
• Pelvic infection; care is needed particularly if you have a history of tubal damage or pelvic infection. Your doctor plans a precaution if necessary.
• Allergy to the contrast material or latex
• Exposure to X-rays; it is at a low level, but for this reason the procedure is not done when pregnancy is possible

One limit of HSG is that interpretation rests on a single image. Although it gives information about the shape of your uterine cavity, HSG does not show the outer contour of your uterus; for this reason additional imaging may be needed in some congenital differences of shape. Small lesions and fine adhesions may also be missed.

What does it mean if the tubes come out open?

If the contrast passes through both of your tubes, your tubes are considered open. This finding indicates that the tubal side is not an obstacle to pregnancy; however, it is not a guarantee that a pregnancy will happen. The other factors are assessed separately.

What happens if the tubes come out blocked or doubtful?

When the contrast material does not pass, the result can be read as "blockage"; however, a false appearance of blockage can also occur from causes such as tubal spasm. It is thought that a chlamydia antibody test may help to distinguish the risk of blockage, but the data behind this recommendation are not yet strong. If blockage is highly likely, additional assessments such as laparoscopy are considered. Surgery or IVF options are discussed with your doctor according to the finding; these decisions are not made on the basis of a single HSG image.

Does the type of contrast affect the result?

In HSG the contrast material may be water-based or oil-based. In this group it is thought that tubal flushing with an oil-based contrast may be preferred over a water-soluble contrast; but this is not a definite recommendation and the data behind it are still limited. You can talk to your doctor about the benefits and risks. Choosing the type of contrast is your doctor's decision.

What methods are used as alternatives to HSG?

Tubal patency and the uterine cavity can also be assessed with other methods. Contrast ultrasound involves no radiation; however, it requires an experienced operator. Ultrasound done with saline is useful for showing findings in the uterine cavity, but a separate method is needed for tubal patency. Hysteroscopy shows the inner surface of the uterus directly. Laparoscopy shows the outer appearance of the tubes and makes it possible to assess tubal patency with dye; however, it is a surgical procedure. The choice is made with your doctor according to your history, your complaint, your allergies and your access.