Hysterosalpingogram (HSG) & Other Imaging Fertility Tests
Hysterosalpingogram & other imaging tests at a glance
- The fertility tests we use for detailed imaging evaluation of the female reproductive system are hysterosalpingogram, ultrasound and sonohysterogram.
- Hysterosalpingogram (HSG) is a common X-ray based test that evaluates a woman’s uterus for proper structure and her fallopian tubes for possible blockages, both of which can result in infertility.
- We perform a pelvic ultrasound of the reproductive organs to evaluate endometriosis, ovarian cysts, polyps, fibroids, pelvic pain and other potential causes of infertility in women.
- A saline sonogram, also known as a sonohysterogram, examines the uterus in a manner similar to an HSG, but this technique allows simultaneous imaging of the entire uterus rather than just the cavity and can sometimes better diagnose uterine fibroids, polyps and structural birth defects.
- Sometimes we need to perform more than one of the imaging tests above for a definitive diagnosis of anatomical conditions that can affect fertility treatment.
HSG testing and other imaging methods to diagnose infertility in women
Our fertility specialists first try to determine a cause of infertility with blood tests, physical exams and discussions with the female and male patients. Beyond that, we often rely on advanced female fertility testing to look for structural issues or abnormal tissue that may be contributing to infertility in the woman.
Pelvic adhesions (scar tissue), pelvic inflammatory disease (PID), endometriosis, fibroids, uterine polyps and blocked fallopian tubes are common factors. But they cannot be seen or diagnosed with the naked eye. For some cases, we may use minimally invasive procedures like hysteroscopy and laparoscopy.
But less invasive forms of imaging tests are often very effective in revealing causes of infertility and pelvic pain in women. These primary female fertility tests include hysterosalpingogram, ultrasound and sonohysterogram, also called sonohysterography, hysterosonography or saline infusion sonogram.
Note that no single imaging test is perfect at detecting all conditions. In some cases, more than one test needs to be performed to thoroughly understand a woman’s reproductive anatomy.
What is a hysterosalpingogram?
A hysterosalpingogram (HSG) is one of the most common diagnostic tests performed to evaluate a woman’s reproductive anatomy. The hysterosalpingogram definition comes from the Greek words for written (gram), uterus (hystera) and fallopian tubes, which ancient medical practitioners thought were trumpet-shaped (salpinx).
An HSG test is an X-ray of the uterus and fallopian tubes using a contrast dye to distend the uterine cavity and fallopian tubes, which are hollow structures with potential spaces. A regular X ray will not show the uterus and tubes, but gently instilling dye into the cavity opens the cavity and tubes and allows them to be imaged on the X-ray. The test is used to detect whether the fallopian tubes are fully or partially blocked. It also reveals whether the uterus is normal in size and shape. These conditions of the uterus and fallopian tubes can affect infertility in women.
Interested in learning more?
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HSG testing procedure
A HSG test takes place in a radiology suite. The patient is awake and can actually watch the test with the fertility specialist as it happens. It usually takes less than five minutes.
The doctor will insert a speculum into the vagina then guide a small catheter through the cervix into the uterus. A type of temporary dye called radiocontrast media is then pushed through the catheter to fill the uterus and tubes, which can be viewed on a monitor. The liquid highlights the organs so they appear clearly on the screen.
The resulting image shows the shape and size the uterus. If fibroids or polyps are present in the uterine cavity, the dye will flow around them, thereby outlining these obstructions. The HSG is a good screening test for uterine anomalies including uterine septum, unicornuate uterus, bicornuate uterus and didelphic uterus.
If the dye flows all the way through the fallopian tubes, it indicates there are no blockages. However, if the dye stops anywhere along either of the tubes, the doctor can see where and whether the tubes are partially or fully closed, which is called tubal disease.
Infertility can result because sperm cannot reach an egg for fertilization in the fallopian tube due to the blockage. Such restriction in the tube also can prevent a fertilized egg (embryo) from traveling to the uterus for implantation and pregnancy.
HSGs can also indicate whether a patient is at increased risk for conditions such as endometriosis. Sometimes the dye flows through the tube but spills in a confined space around the tube rather than flowing freely throughout the pelvis. This increases the risk of pelvic adhesions, which can be seen in endometriosis and can affect fertility. One limitation of the HSG test is that it does not show the muscular layer of the uterus or the ovaries directly.
Hysterosalpingogram risks and pain
HSG is considered a very safe procedure. There is some discomfort for the patient during an HSG, but not much pain. Often the doctor will advise taking an anti-inflammatory medication like ibuprofen before the procedure to help ease the discomfort of the catheter insertion and uterine cramping. Otherwise no anesthesia is involved.
Having a full bladder prior to the procedure can often make catheter insertion much easier and less painful. The fullness acts to distend the bladder, which pushes the uterus into a straight position rather than a curved position in many patients. This makes catheter insertion easier.
Post procedure, there can be uterine cramping and, in very rare cases, possible pelvic infection, which could cause tubal scarring. Antibiotics are prescribed if a patient is at increased risk for tubal infection.
The HSG image reveals what is essentially a shadow of the patient’s uterus and fallopian tubes, and there are times when these shadows can be incomplete. In these cases, additional tests may be necessary.
Ultrasound female fertility test
A pelvic ultrasound uses sound waves to produce a picture of reproductive organs and structures in a woman’s pelvis. It provides an excellent view of the cervix, inner lining of the uterus (endometrium), uterus, and ovaries, as well as the bladder and blood flow to these organs. Fallopian tubes are not generally visible on ultrasound unless they are damaged and distended with fluid.
Ultrasound is extremely useful in diagnosing a wide range of conditions including pelvic pain, fibroids, polyps, uterine malformations and endometriosis, all of which can cause infertility. There are two types of ultrasound: one in which a technician runs a hand-held probe over the abdomen (transabdominal), and one in which a wand is inserted into the vagina (transvaginal).
The test can typically be performed in a fertility specialist’s office. The patient is awake and can watch it in real time on a monitor. There is very little to no pain involved.
Sonohysterogram (sonohysterography), also called hysterosonography or saline infusion sonogram
Sonohysterogram (SHG) is a test of the uterus that combines ultrasound with the HSG technique, except saline is used instead of radiocontrast dye. Doctors conduct it for several reasons including diagnosing causes of female infertility due to problems with the uterus, fallopian tubes and recurrent miscarriage, according to the American College of Obstetricians and Gynecologists.
The specialist will insert a catheter through the cervix and fill the uterus with sterile saline fluid. Then ultrasound technology is used to visualize and measure the uterus and endometrium, which is the lining of the uterus. This saline sonography test is excellent at detecting uterine polyps, fibroids, endometrial abnormalities, lesions, and congenital defects.
Like an HSG test, there is not much pain associated with this test, but there may be mild discomfort and possible post-procedure cramping; typical pre-procedure preparation with ibuprofen minimizes discomfort and having a full bladder can also aid the ease of catheter insertion, much like the HSG test preparation.