Hysterosalpingography

Hysterosalpingography is a radiological examination that allows visualization of the uterus and fallopian tubes. By using contrast material during the procedure, the structural status of the reproductive organs is evaluated and problems such as obstruction are identified in detail.

Performed with the aim of evaluating tubal patency, this examination provides critical information in infertility investigations by showing the speed and distribution of contrast passage. Structural abnormalities are clearly defined at this stage.

HSG assessments focusing on the detection of intrauterine pathologies provide high diagnostic value in identifying formations such as polyps, fibroids or adhesions. In this way, treatment planning can be carried out more accurately.

This approach, which explains the clinical follow-up requirements after the procedure, provides clear information on the management of possible mild cramps and temporary discomfort. It helps the patient to adapt to subsequent diagnostic and therapeutic stages.

What Is Hysterosalpingography?

Hysterosalpingography (HSG) is an X-ray imaging method with contrast material used to evaluate the structure and patency of the uterus (uterus) and fallopian tubes. It is most commonly used in infertility investigations. During the procedure, a special fluid is administered through the cervix, allowing clear visualization of whether the tubes are open and of the intrauterine structures. It is painless or completed in a short time with mild cramps.

Why Is an HSG (Uterine X-ray) Requested?

HSG is a diagnostic method designed to answer two critical questions: First, are the fallopian tubes — where sperm meets the egg and the fertilized embryo starts its journey toward the uterus — open? Second, is the shape of the uterine cavity, where the embryo will implant and grow, normal, and is there any space-occupying lesion (such as a polyp or fibroid) or adhesion inside it?

A significant portion of female infertility is due to tubal obstruction or damage. Likewise, structural abnormalities within the uterus can prevent embryo implantation or lead to miscarriages. HSG provides us with highly valuable information about these two vital areas in a single procedure. Therefore, it is usually one of the first basic tests requested in couples presenting with infertility. A normal HSG result provides strong reassurance that the tubes are open, whereas abnormal findings directly guide us to the source of the problem and allow us to determine the treatment plan.

When Is an HSG (Uterine X-ray) Necessary in Infertility Evaluation?

The decision to perform an HSG depends on the couple’s specific situation, but there are some common scenarios:

The primary indication is infertility assessment: If pregnancy has not been achieved despite 12 months of regular, unprotected intercourse in women under 35, or 6 months in women aged 35 and older, an infertility workup is initiated. As a standard part of this workup, HSG is requested to visualize the anatomical status of the uterus and tubes.

Recurrent Pregnancy Loss (RPL): In the case of two or more pregnancies ending in miscarriage, the underlying cause must be investigated. Structural abnormalities in the uterine cavity (congenital uterine anomalies, polyps, fibroids or adhesions) may be responsible for these losses. HSG is frequently used to screen for such problems.

Post–Tubal Ligation (Tubes Tied): In women who have undergone tubal ligation for permanent contraception, an HSG may be required (especially if performed by a hysteroscopic method) about three months after the procedure to confirm that the procedure has been successful and that the tubes are completely blocked.

Are There Problems That an HSG Cannot Show or Diagnose?

Yes, this is a very important point. It must be remembered that HSG essentially shows the inside of the uterine cavity and the internal lumen of the tubes. Therefore, it cannot diagnose problems outside these structures.

Some conditions that HSG cannot diagnose or evaluate are:

• Endometriosis (chocolate cysts)
• The condition of the ovaries or ovarian cysts
• Fibroids located within the uterine muscle (intramural) or on the outer surface of the uterus (subserosal) that do not compress the cavity
• Adhesions around the tubes (peritubal adhesions)

HSG can only raise suspicion of adhesions around the tubes. For example, even if the contrast passes through the tube, if it does not disperse freely but collects in a localized area (as if pooling), this may suggest adhesions at or around the distal end of the tube. However, a definitive diagnosis of such conditions can only be made by laparoscopy (keyhole surgery) through direct visualization of the pelvic cavity.

Who Should Not Undergo an HSG (Uterine X-ray)?

Appropriate patient selection is critical for HSG to be a safe and beneficial test. In certain situations, this procedure should absolutely not be performed.

Absolute contraindications include:

• Pregnancy or suspected ongoing pregnancy
• Active or suspected pelvic infection (Pelvic Inflammatory Disease – PID)
• Severe, active uterine bleeding that would interfere with the procedure

Caution is also required in individuals with a known history of severe allergy to iodinated contrast media or seafood. In such cases, ultrasound-based methods that use non-iodinated fluids (e.g. saline infusion sonography) may be a safer alternative. In patients with serious thyroid disease (such as Graves’ disease), iodinated contrast must be used carefully, as iodine loading can cause problems.

What Is the Optimal Timing for an HSG (Uterine X-ray)?

The timing of the procedure is critical for both safety and image quality. HSG should be performed after menstrual bleeding has completely ended but before ovulation, that is, in the early to mid-follicular phase of the cycle.

This generally corresponds to cycle days 5 to 12. There are two main purposes for this timing:

To ensure that the patient is not pregnant (eliminating the risk of harming an early pregnancy through radiation or the procedure).

To capture the uterine lining (endometrium) at its thinnest. This allows better visualization of the uterine cavity and prevents a thickened endometrium from being misinterpreted as a polyp or fibroid.

What Preparations Are Needed Before an HSG (Uterine X-ray)?

Preparation before an HSG is relatively simple but important.

• Pregnancy Test: Immediately prior to the procedure, a urine pregnancy test is mandatory to definitively rule out a possible pregnancy.
• Sexual Abstinence: To increase safety, it is generally recommended to avoid sexual intercourse from the onset of menstrual bleeding until the HSG procedure is completed.
• Pain Management: The injection of contrast fluid during HSG can cause cramps similar to menstrual pain. To minimize these cramps, it is commonly recommended to take a non-steroidal anti-inflammatory (NSAID) painkiller such as ibuprofen about 30–60 minutes before the procedure. This is a standard, low-risk practice.

Is It Necessary to Take Antibiotics Before an HSG (Uterine X-ray)?

Routine prophylactic antibiotics before HSG are not recommended for every patient. Overall, the risk of infection after the procedure is quite low (approximately 1.4% to 3.4%).

Antibiotic prophylaxis (preventive use of antibiotics) is usually reserved for certain situations that carry a higher risk of infection:

• Women with a history of pelvic infection (PID)
• Patients in whom “hydrosalpinx” (fluid accumulation inside the tube) is detected during the procedure

If swollen, blocked tubes (hydrosalpinx) are observed during the procedure, this may indicate an existing chronic infection, and antibiotics may be started to prevent post-procedural infection.

How Is an HSG (Uterine X-ray) Performed Step by Step?

HSG is usually performed on an outpatient basis in radiology units or gynecology clinics, and the active procedural time is about 5 to 10 minutes.

• Positioning: The patient is placed on the X-ray (fluoroscopy) table in the gynecological examination position.
• Speculum and Cleansing: A speculum is inserted into the vagina to visualize the cervix. The cervix is carefully cleansed with an antiseptic solution (such as povidone-iodine) to prevent bacteria from entering the uterus.
• Catheter Placement: To access the uterine cavity, a thin, special catheter (tube) is inserted through the cervix. The tip of this catheter usually has a small balloon to seal the cervical canal and prevent backflow of the injected fluid.
• Injection of Contrast Material: Through the catheter, an iodinated contrast medium (radio-opaque dye) is slowly and carefully injected into the uterine cavity. It is normal to feel cramping while this fluid is being injected.
• Imaging: While the contrast material is being injected, its movement is observed in real time using fluoroscopy, and a series of images are obtained. These images show:
• • Filling of the uterus with the contrast fluid,
  • The shape of the uterine cavity,
  • Passage of the fluid through the tubes,

And finally, the spillage of the contrast from the distal ends of the tubes into the abdominal cavity (“spill”).

Important Technical Notes: Care must be taken to avoid introducing air bubbles into the uterine cavity during the procedure. Air bubbles also appear as “filling defects” on X-ray and may be mistakenly interpreted as polyps.

In addition, pain during the procedure or manipulation of the cervix may cause a temporary spasm at the uterine corners where the tubes join the uterus, known as “cornual spasm”. This spasm may falsely make a patent tube appear blocked. This is one of the “false positive” results of HSG, and an experienced clinician always keeps this possibility in mind.

What Should I Expect After an HSG (Uterine X-ray)?

Most women can return to their normal daily activities immediately after the procedure. Some mild post-procedural effects are expected.

Mild effects after the procedure are normal:

• Mild to moderate cramping (usually resolves within a few hours)
• Light spotting-type vaginal bleeding lasting one or two days
• Sticky, medicated vaginal discharge due to some of the contrast fluid flowing back

During this period, sanitary pads rather than tampons are recommended to reduce the risk of infection.

After an HSG (Uterine X-ray), in Which Situations Should I Seek Urgent Medical Attention?

Although HSG is a very safe procedure, complications can rarely occur. It is important to be alert for signs of infection.

The following symptoms may indicate infection or a serious problem and require immediate medical attention:

• Progressively increasing or severe pelvic pain
• High fever
• Chills
• Foul-smelling vaginal discharge
• Heavy or prolonged vaginal bleeding (similar to menstrual bleeding)

Fortunately, serious complications such as fainting (vasovagal reaction), uterine perforation or severe allergic reactions to the contrast material occur in less than 1% of cases.

What Does a Normal HSG (Uterine X-ray) Look Like?

In a normal HSG, the uterine cavity appears as a smooth-walled, triangular space filled with contrast. The contrast then flows from the uterine cornua into the fallopian tubes as thin, regular lines. Finally, the fluid is seen spilling freely from the fimbrial (fringed) ends of both tubes into the abdominal cavity and dispersing around the bowel loops. This “free spill” confirms that the tubes are open and healthy.

Which Tubal Problems Can Be Detected on HSG?

Tubal disorders are among the most common causes of female infertility. HSG is the primary method for detecting such problems.

• Tubal Obstruction (Occlusion): A situation in which the contrast medium cannot progress beyond a certain segment of the tube and does not spill into the abdominal cavity.
• Proximal Obstruction: Obstruction in the segment of the tube closest to the uterus. As mentioned earlier, this may be due to transient “cornual spasm” induced by the procedure and is therefore of limited reliability. In fact, in up to about 60% of patients with this diagnosis, repeat HSG or laparoscopy later shows that the tubes are actually open.
• Distal Obstruction: Obstruction at the distal (fimbrial) end of the tube. This is usually a more serious finding that develops after prior pelvic infections, endometriosis or pelvic surgeries and is the direct cause of “hydrosalpinx”.
• Hydrosalpinx: One of the most critical findings. When the distal end of the tube is blocked, fluid gradually accumulates inside, and the tube becomes distended. On HSG, this appears as a dilated, tortuous, “sausage-shaped” structure filled with contrast, with no spill into the abdominal cavity.
• Salpingitis Isthmica Nodosa (SIN): A condition in which nodular thickening and small outpouchings (diverticula) develop in the proximal (uterine) portion of the tube. On HSG, this appears as small, sac-like extravasations of contrast material extending outward from this segment of the tube. This condition is strongly associated with both infertility and an increased risk of ectopic pregnancy.
• Peritubal Adhesions: HSG cannot directly visualize adhesions. However, if the contrast that has passed through the tube does not disperse freely but becomes trapped in a small, irregular area around the tube (pooling), this strongly suggests the presence of adhesions surrounding the tube.

Which Intrauterine Problems Can Be Seen on HSG?

Intrauterine pathologies typically appear on HSG as “filling defects”, meaning areas within the uterine cavity that are not filled by contrast.

However, it is important to remember that the specificity of HSG in detecting intrauterine pathologies is low. Many things that appear as “filling defects” (air bubbles, clots, a thickened endometrium) may not actually be polyps or fibroids (false positives). Therefore HSG is a screening test for the uterine cavity; definitive diagnosis usually requires saline infusion sonohysterography (SIS) or hysteroscopy.

Common intrauterine filling defects include:

• Endometrial polyps
• Submucosal fibroids (fibroids compressing the uterine lining)
• Intrauterine adhesions (synechiae / Asherman syndrome)
• Congenital uterine anomalies (septum, double uterus, etc.)

How Are Congenital Uterine Anomalies Recognized on HSG?

HSG outlines the inner contour of the uterine cavity very clearly, which makes it an excellent tool for screening congenital uterine shape abnormalities (Müllerian anomalies).

However, HSG has a critical limitation: it cannot show the outer contour (serosal surface) of the uterus. Therefore, when it shows a septum in the uterine cavity, it cannot definitively distinguish whether this is a “septate uterus” (normal outer contour, internal septum) or a “bicornuate uterus” (both the cavity and the outer surface are indented, double-horned uterus). This distinction is extremely important because it completely changes the treatment approach and must be made by 3D ultrasound or MRI.

Some common anomalies that can be visualized include:

• Uterine septum (septate uterus)
• Unicornuate uterus or bicornuate uterus
• Uterus didelphys (double uterus)
• Arcuate uterus (heart-shaped uterus)

Why Is HSG Requested Before IVF Treatment?

Patients often ask: “If we are going to have IVF and IVF bypasses the tubes (that is, it does not require functional tubes), why do we still need to have an HSG done?”

This is a very valid question, and the answer lies in two critical factors that directly affect IVF success.

To Detect Hydrosalpinx: The most important reason to request HSG before IVF is this. Tubal occlusion with the development of hydrosalpinx severely compromises the success of IVF. The presence of hydrosalpinx reduces embryo implantation and pregnancy rates by approximately 50% and doubles the risk of miscarriage. The reason is that the fluid inside the hydrosalpinx is toxic (embryotoxic) and continuously refluxes into the uterine cavity, disrupting the endometrial environment required for implantation.

To Evaluate the Uterine Cavity (the Embryo’s “Nest”): In IVF, the embryo is created in the laboratory and placed directly into the uterus. This “nest” needs to be optimal. HSG screens for polyps, fibroids, adhesions or congenital septa that could mechanically impede embryo implantation. If an abnormality is suspected on HSG, correcting it with hysteroscopy before embryo transfer maximizes the chances of treatment success.

What Should Be Done If Hydrosalpinx Is Detected on HSG?

Detection of hydrosalpinx on HSG is a critical finding that requires mandatory intervention in the IVF treatment pathway. Proceeding directly to embryo transfer in the presence of hydrosalpinx would knowingly reduce the chance of success by about 50%.

Therefore, the standard approach is to interrupt the connection between this toxic fluid and the uterine cavity before embryo transfer.

• Laparoscopic Salpingectomy (Removal of the Tube): This is the gold standard treatment. The affected, fluid-filled tube is surgically removed via laparoscopy (keyhole surgery). This definitively stops the flow of toxic fluid into the uterus and restores IVF success rates to the level of patients without hydrosalpinx.
• Proximal Tubal Occlusion: If removing the tube is too risky because of dense adhesions (for example, the risk of bowel injury), an alternative is to occlude the tube at its uterine junction (proximally) laparoscopically or hysteroscopically. The goal is the same: to prevent the fluid from reaching the uterine cavity.

If a Polyp or Fibroid Is Seen in the Uterus on HSG, Is Treatment Required Before IVF?

Yes. The uterine cavity must provide the best possible environment for embryo implantation. Intrauterine lesions suspected on HSG and confirmed by saline infusion sonohysterography (SIS) or hysteroscopy are generally treated before starting an IVF cycle.

Polyps, submucosal fibroids and adhesions can mechanically interfere with embryo implantation, cause chronic inflammation in the uterine cavity or impair endometrial receptivity.

• Operative Hysteroscopy: This is the gold standard method for both definitive diagnosis and simultaneous treatment of these problems.
• Myomectomy (Fibroid Removal): Hysteroscopic removal of fibroids that grow into the uterine cavity (submucosal fibroids) is a standard approach.
• Laparoscopic Adhesiolysis: Cutting intrauterine adhesions to restore normal cavity shape and volume increases the chance of implantation.

Does HSG Have a Therapeutic Effect, Such as “Opening” the Tubes?

Beyond its diagnostic purpose, HSG has long been observed to have a potential therapeutic benefit, known as the “tubal flushing” effect. The procedure itself appears to slightly increase the chance of spontaneous pregnancy in some women, especially in the first 3 months after HSG.

There are several theories about how this effect occurs:

• Mechanical Cleaning
• Effects on the Immune System (Immunomodulation)
• Effects on the Uterine Lining

The most widely accepted theory is that the pressurized contrast fluid “flushes out” mucus plugs, cellular debris or thin, filmy adhesions inside the tubes, thereby reopening the pathway for sperm and egg.

For HSG, Is Oil-Based or Water-Based Contrast Material Better?

This debate around the “therapeutic effect” is directly related to which type of contrast agent is used. Traditionally, both water-based contrast media (WBCM) and oil-based contrast media (OBCM) have been used.

Large, multicenter randomized controlled trials and meta-analyses have clearly shown that oil-based contrast media are superior to water-based ones in enhancing fertility.

HSG performed with oil-based contrast, compared with water-based contrast, has been shown to increase ongoing pregnancy and live birth rates in the subsequent six months by about 10%. This evidence has shifted the role of oil-based HSG, particularly in certain groups with unexplained infertility, from a purely diagnostic test to a low-cost, first-line therapeutic intervention.

However, oil-based agents also have a different risk profile: slower clearance from the body, a rare risk of fat embolism, and the potential to temporarily affect thyroid function due to high iodine content. Therefore, they should be used with caution, especially in patients with a history of thyroid disease.

Can Ultrasound-Based Methods (SIS, HyCoSy) Be Used Instead of HSG?

Yes, in recent years ultrasound-based techniques that do not involve radiation and can be performed in an office setting have emerged as strong alternatives to HSG.

• Evaluation of the Uterine Cavity: Saline infusion sonohysterography (SIS) is far superior to HSG for assessing the uterine cavity. Compared with hysteroscopy, SIS has much higher accuracy than HSG, and the “false positive” rate (appearance of a polyp that is not truly present) seen on HSG is very low with SIS.
• Assessment of Tubal Patency: Hysterosalpingo-contrast sonography (HyCoSy) or hysterosalpingo-foam sonography (HyFoSy) are used to assess tubal patency with ultrasound. In these methods, a special foam or contrast agent is injected into the uterus, and its passage through the tubes is monitored by ultrasound. Advantages include the absence of radiation and generally less pain.

However, HSG is still considered better at showing detailed tubal anatomy, internal tubal abnormalities and specific pathologies such as SIN.

What Is the Difference Between HSG and Hysteroscopy?

Although these two procedures are often confused, their purposes and methods are completely different.

HSG (Uterine X-ray): An X-ray procedure. It shows the “silhouette” of the uterine cavity and the tubes. It is primarily used as a screening test for tubal patency and intrauterine abnormalities. It does not provide a definitive diagnosis; it merely raises suspicion.

Hysteroscopy: Involves inserting a thin instrument with a camera (hysteroscope) into the uterine cavity. It allows direct visualization of the uterine interior. It is the gold standard diagnostic method for intrauterine pathologies (polyps, fibroids, adhesions, septa). Its greatest advantage is the “see and treat” principle — once an abnormality is detected, it can be corrected surgically in the same session (operative hysteroscopy).

In short, HSG says, “There may be a problem here,” whereas hysteroscopy says, “This is the problem, and I am correcting it now.”

What Is the Difference Between HSG and Laparoscopy (Keyhole Surgery)?

This is another important distinction. Both can evaluate the tubes, but from completely different perspectives.

HSG (Uterine X-ray): Shows the inside of the uterus and tubes. It cannot show the outside. It is minimally invasive and does not require anesthesia.

Laparoscopy (Keyhole Surgery): A surgical procedure performed under general anesthesia by inserting a camera through the navel into the abdominal cavity. It shows the outer surfaces of the uterus, tubes and ovaries, as well as all pelvic structures.

Laparoscopy is the only method that can diagnose problems that HSG cannot detect, including:

• Endometriosis (chocolate cysts and implants)
• Adhesions around the tubes
• Fibroids on the outer surface of the uterus

The gold standard for assessing tubal patency is actually “chromopertubation” during laparoscopy, in which blue dye (such as methylene blue) is injected through the cervix and its spillage from the distal ends of the tubes is observed. However, because laparoscopy is a surgical procedure, it is not performed solely for screening; instead, it is reserved for situations where HSG has shown an abnormality, or when suspicion of endometriosis/adhesions is very high, in order to provide both diagnosis and treatment (releasing adhesions, treating endometriosis, removing the tube, etc.).

Frequently Asked Questions