Infertility Testing & Diagnostics

Hysterosalpingogram (HSG) and Hysterosonogram (HSN)

Diagnosis of infertility causes requires comprehensive testing on both the female and male partners. On the female side, infertility testing usually involves hormonal testing to determine the patient's ovarian reserve, diagnostic imaging to see if there are any anatomical problems (such as blocked fallopian tubes or uterine fibroids), and immunological testing to rule out any maternal autoimmunity. Knowing the root cause of a couple's infertility is the first step toward successful fertility treatment. Therefore, at CHR, as a comprehensive fertility center in New York, NY, we take infertility testing seriously. As explained on this page, CHR performs almost all diagnostic imaging in-house, so that we can be sure we have the most accurate diagnosis of infertility. Not having to visit separate facilities for multiple tests is, of course, a boon for our patients, too.

Hysterosalpingogram (HSG)

hysterosalpingogramThis is the standard, basic x-ray study of the uterus. It is designed to study the inside of a uterus (the uterine cavity). Hysterosalpingogram (HSG) gives us a basic assessment of whether the fallopian tubes are patent (unobstructed).

This basic procedure is offered by most hospital radiology departments and can be performed by a radiologist or a gynecologist.

How hysterosalpingogram (HSG) is performed

The process is simple. The patient is asked to lie down just as if she were to have a PAP smear. A speculum is placed in the vagina and the opening to the uterus (called the cervix) is visualized by the doctor. After cleaning the cervix with an iodine solution, a long, narrow, flexible catheter is inserted through the opening of the cervix until the tip is inside the uterine cavity. A balloon on the end of the catheter is inflated to hold the catheter in place. The catheter is connected to plastic tubing through which a special dye is passed into the uterus. This dye looks like water to the naked eye, but it appears on x-ray film because it blocks the passage of the x-rays. On the film, everywhere the dye flows looks white.

As the dye fills the uterus, x-rays are taken every few seconds. This reveals any abnormalities inside the uterus such as a split cavity, uterine fibroids or adhesions.

As more dye flows into the uterus, some will begin to fill the fallopian tubes. If the tubes are unobstructed (patent) along their entire course, eventually the dye will "spill" out the other side.

Contact us about infertility testing through hysterosalpingogram.

Hysterosalpingogram (HSG) needs a correct interpretation by an fertility expert

hysterosalpingogramSpilling of the dye, however, does not always indicate normal fallopian tubes. It takes an experienced expert to correctly interpret "normal" tubal anatomy on HSG. Indeed, in our opinion, the interpretation of HSG films is likely the most frequently falsely interpreted test in medicine!

We constantly see patients with diagnosis of "normal tubes" on HSG, who, when we closely examine their X-ray films, turn out to have obvious tubal disease. These patients often come to CHR with the dubious diagnosis of "unexplained infertility," only because their tubal problem hasn't been discovered during previous HSG procedures. Part of the problem may lie in the fact that the HSG procedure often falls between medical specialties, as radiologists perform almost all HSG.

Our radiology colleagues focus on whether the tubes are "open" when they perform and interpret HSG. This is a fundamentally different question from what we, fertility specialists, try to answer by HSG: For us, the question is whether the tubes are "normal." Normal tubes, of course, have to be open; open tubes, however, are not always normal! As explained below, an open tube may have functional problem that prevents it from "grabbing" the egg from the ovary. Such subtle tubal issues really require a fertility specialist to be diagnosed. This is why CHR keeps HSG procedures in-house.

At CHR, digital images taken during hysterosalpingogram are stored electronically. These images can then be manipulated in a number of different ways to help a physician distinguish subtle abnormalities. Typically 50 to 60 images are generated from a basic HSG.

Selective Hysterosalpingogram

hysterosalpingogram (HSG)Sometimes, during hysterosalpingogram (HSG), a physician might discover that the dye will not flow into the tube(s) because of an obstruction or "spasm" of the muscle around the opening of the tube. With an HSG alone, it is impossible to distinguish an obstruction (which will cause infertility) from spasm (which is not a problem for fertility prospects). Furthermore, if a true obstruction exists, with an HSG alone, there is no way to bypass it. Selective hystrosalpingogram is a way to overcome this problem. It is both a diagnostic and therapeutic procedure, which CHR physicians can perform in-house.

hysterosalpingogram (HSG)With selective salpingography, a thinner, flexible catheter is run inside the HSG catheter. With the help of the x-ray machine, this smaller catheter is directed right into the opening of the fallopian tube. Once this is done, dye can be introduced directly into the fallopian tube. In this way, it is possible to distinguish a normal, patent, fallopian tube whose opening is in spasm from tubes with obstruction. Fallopian tubes with an actual obstruction can also be opened by the higher pressures, which can be achieved with selective salpingography, though this is not always possible.

Tubal perfusion pressure (TPP) measurements

Sometimes, even if a fallopian tube is unobstructed, the tube does not function very well. Most people, including many physicians, think of fallopian tubes as simple pipes that allow egg and sperm to meet, and the fertilized egg to reach the uterus. However, in actuality, a fallopian tube is a much more dynamic organ. At the end of a fallopian tube closest to the ovaries, there is a part called the fimbriae. Fimbriae are very delicate skin-like folds, which "grab" the ovulated eggs from the ovary with gently sweeping motions. When this function is compromised, even a seemingly "open" fallopian tube no longer can serve its purpose. Therefore, even open tubes can be diseased. The most frequent condition affecting fimbriae, causing their agglutination, is endometriosis.

With the use of specialized computer software, pressure transducers, and selective salpingography, we now have the capability to more accurately measure the functions of fallopian tubes. This is done by measuring pressures during selective salpingography. Tubes that are rigid and diseased need higher pressures to move dye through, whereas normal tubes require only minimal pressures.

Does this matter? We believe so! In a 1995 study by CHR investigators, we demonstrated that women with high TPP measurements are more likely to have endometriosis than women with low pressures. More importantly, women with high TPP measurements take longer to become pregnant and do not achieve pregnancy as often as women with low TPP measurements. TPP measurements have since become part of infertility diagnosis at many respected fertility centers.

CHR physicians have used the information from SS/TPP measurements to recommend that women use IVF to achieve pregnancy, rather than continue trying to conceive using their fallopian tubes. Because IVF circumvents the fallopian tubes, it is an ideal solution for women with tubal infertility.

Wire Guide Canalization

When selective salpingography is insufficient to remove a tubal obstruction, wire guide canalization may be performed to make the fallopian tube patent. In this procedure, thin, flexible wire is carefully threaded through a selective salpingography catheter, and passed directly inside a fallopian tube (see video below). This technique, which is analogous to using a plumber's "snake" to open a blocked drain, is another technique CHR physicians developed to open a blocked tube. CHR's Medical Director, Dr. Gleicher, invented the concept of recanalizing obstructed fallopian tubes with catheters under X-ray control. Today this is a technique widely practiced by radiologists. However, to the best of our knowledge, CHR is the only fertility center offering this treatment in-house.

Another use for this technique is to lower the TPP measurements in women with high levels. However, there is no convincing data that reducing TPP in this way allows these women to achieve a pregnancy rate similar to those who have a low TPP.

Trained and experienced physicians perform all of these procedures at CHR. They take little additional time compared to a basic HSG, and provide considerable additional, clinically useful information as well as treatment options.

Hysterosonograms (HSN)

This is sort of a combination of a HSG and ultrasound. However, instead of using radio-opaque dye and x-rays to "see" the uterus, we use saline (salt water) and high-resolution ultrasound.

The result is a very sensitive method for visualizing abnormalities inside the uterus. Hysterosograms are more "comfortable" than HSGs, which sometimes causes cramping. Hysterosonograms, however, cannot replace hysterosalpingograms when it comes to evaluations of fallopian tubes.

Infertility Diagnosis through Hysterosonograms

Hysterosonogram showing Intrauterine adhesions

hysterosonograms (HSN)

This patient came to us having failed five IVF cycles at another program. The hysterosonogram revealed scar tissue (adhesions) inside the uterine cavity. Interestingly, an HSG performed previously did not demonstrate any adhesions.

Another hysterosonogram showing example of adhesions in the uterus

hysterosonograms (HSN)

Hysterosonogram demonstrating Intra-abdominal adhesions

hysterosonograms (HSN)

Fluid which passed through the fallopian tubes allowed this view of pelvic adhesions from the fallopian tube to the uterus.

High-Resolution Ultrasound

Examples of early intra-uterine pregnancy using high resolution ultrasound


This infertility patient conceived with the use of gonadotropins (injectable fertility medications). The amnion (thin membrane surrounding the embryo during pregnancy) is clearly seen.


Using color flow doppler, blood flow is seen in the early embryo.

Next Step

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Last Updated: January 16, 2013