An Example X-Ray of a normal HSG	An example X-Ray of an abnormal HSG

Infertility due to blocked fallopian tubes was a common cause of infertility in the 1970’s and 1980’s. Some textbooks from that era quote an incidence as high as 25% of all infertility causes. At Pacific Fertility Center in 2005, only 10% of our in vitro fertilization patients were noted to have a tubal factor contributing to their infertility. Fallopian tube damage is most commonly due to prior infection with a sexually transmitted disease such as gonorrhea or Chlamydia. Most chlamydial pelvic infections are relatively asymptomatic and may go unrecognized; therefore many patients with tubal obstruction are unaware they have a tubal problem. Better safe-sex practices and improved screening of young women are possible factors for the lower incidence of tubal disease we are seeing, at least in our Bay Area infertility population.

Even though there is less tubal factor infertility these days, if there is a tubal obstruction, the course of fertility treatment becomes quite definitive: in vitro fertilization. No other treatments, including surgery, are likely to result in a healthy intra-uterine pregnancy. Therefore, we are still advocating some type of screening test for tubal factor in the evaluation of infertile couples.

There are two common ways to determine whether there is tubal obstruction. One is surgery, where dye is passed through the cervix, uterus and tubes, and there is direct visualization of the flow of the dye out the ends of the tubes into the pelvis. The other is the HSG, or hysterosalpingogram. The HSG is an X-ray procedure that involves placing into the cervix a small flexible catheter with a balloon around the tip to hold the catheter in place and close off the cervical opening. Radiographic contrast dye is then instilled into the uterine cavity, using a syringe attached to the tube. Under X-ray visualization, the dye is tracked into the uterine cavity and into the tubes. Pictures are taken during this process to document the shape of the uterine cavity and whether or not the dye enters and flows through both tubes into the pelvis.

HSG procedures are usually performed by radiologists; however, if there is difficulty placing the catheter securely into the cervix, the radiologist may ask the patient’s gynecologist to assist. This test is valuable in determining tubal blockages, but it has some disadvantages. It is very important to get the balloon properly inflated in the cervix to keep enough pressure on the fluid (no back flow into the vagina) so it will enter the fallopian tubes. Unfortunately, this pressure on the walls of the uterus can cause the uterus to contract, causing the patient to experience significant cramping. For this reason, it is recommended the patient take 2 or 3 ibuprofen prior to the procedure.

In some cases, the pressure is enough to cause the smooth muscle walls of the fallopian tubes themselves to spasm, blocking any dye from entering the tube. Sometimes the dye flows so easily through one tube that there is not enough pressure generated to get the dye to fill the other tube. These are some of the drawbacks of the procedure. This is why, even when we get a report of one-sided tubal obstruction, we are often skeptical that this is really due to some abnormality of the tube.

Although there are some false positives associated with this test, if the dye fills both tubes and does not flow out the ends of the tubes, this is highly suggestive of true tubal obstruction. In this instance, IVF is indicated.

Tags: Female Infertility, Fertility Testing, IVF - In Vitro Fertilization

This entry was posted on Saturday, November 15th, 2008 at 12:27 pm and is filed under Critical Review. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.