Visualizing Female Reproductive Anatomy: How an HSG Works

Dec 11, 2023 8:15:00 AM Posted by Iowa Radiology

Iowa Radiology hysterosalpingogram

What is an HSG?

A hysterosalpingogram (HSG) is a real-time X-ray test that examines the uterus and fallopian tubes. It relies on fluoroscopy, which allows doctors to visualize the flow of contrast dye as it occurs to identify abnormalities in the reproductive system. It’s often used to investigate fertility issues such as recurrent miscarriage or difficulty conceiving. By highlighting the features of the uterus and fallopian tubes, the exam can reveal blockages and uterine anomalies like adhesions, fibroids, and other masses.

How does HSG guide fertility treatment?

The information an HSG provides can be an important part of planning fertility treatment. When doctors can pinpoint physical barriers to conception or the ability to carry a pregnancy to term, they can better tailor their efforts to a specific patient’s needs.


Blocked Fallopian Tubes

Fallopian tube blockage is a common cause of infertility. It can arise as a result of issues like pelvic inflammatory disease, endometriosis, ectopic pregnancy, or scar tissue from prior surgeries, including treatments like fibroid removal as well as tubal ligation. Often, women with fallopian tube blockages do not experience any symptoms, but the conditions that cause blockage may cause symptoms like pain or excessive bleeding. In many cases, difficulty conceiving is the first sign of blocked fallopian tubes.


With an HSG, doctors can visualize the nature and location of blockages, allowing them to home in on the course of treatment that holds the greatest likelihood of success. For example,

  • Blockages that occur close to the uterus can often be removed using an imaging-guided procedure called tubal cannulation.
  • Hydrosalpinx, in which fluid builds up in the fallopian tubes, is a factor in 10% to 20% of cases of fallopian tube blockage. It is often treated by removing part of the fallopian tube (salpingectomy) or creating a new pathway from the ovary to the fallopian tube (salpingostomy or fimbrioplasty). While in vitro fertilization (IVF) can help patients achieve pregnancy while bypassing the fallopian tubes, hydrosalpinx can cause problems after embryo implantation.
  • Ectopic pregnancy describes the implantation of an embryo outside of the main uterine cavity. Most often, this occurs in the fallopian tube. Ectopic pregnancies present serious risks to the patient’s health and life. Therefore, identifying them as early as possible is critical. Previous fallopian tube surgery, pelvic inflammatory disease, a history of ectopic pregnancies and pregnancies that occur while using certain forms of birth control are associated with increased risk of ectopic pregnancy.


Uterine Abnormalities

An HSG can also identify uterine problems that can interfere with conception and healthy pregnancy. Various issues like adhesions, benign tumors, and cancers can undermine fertility. Investigating with HSG allows doctors to clearly visualize the uterine interior so they can locate such anomalies and develop an appropriate treatment plan. This could include surgery to correct the underlying problem or simply influence which type of assisted reproductive technology is chosen.


Fertility Treatment Options

A variety of technologies are available to address infertility. Which a doctor chooses can depend, in part, on what an HSG reveals. As mentioned above, IVF can be used to bypass the fallopian tubes, achieving fertilization outside the body in a laboratory so embryos can be directly implanted into the uterus. Other interventions include

  • Medication to induce ovulation in patients who don’t experience regular ovulation
  • Intrauterine insemination (IUI), in which sperm is introduced into the uterus during ovulation to allow more sperm to reach the fallopian tubes
  • Medication to induce superovulation, often combined with IUI treatment
  • Use of donated eggs for patients who don’t respond to ovulation induction or have other barriers to egg production

Additional imaging tests may be needed to determine the best course of treatment.


What other imaging tests are used to guide treatment for fertility issues?

While HSG provides valuable information about female reproductive anatomy, other tests are often used to investigate fertility issues. These often include pelvic ultrasound, which may incorporate sonohysterography. In a sonohysterogram, a saline solution is introduced into the uterus using a thin, flexible catheter. This expands the uterine cavity to create clearer sonogram images than can be obtained using traditional transvaginal ultrasound.


What happens during an HSG exam?

In a hysterosalpingogram, a technologist uses a speculum to access and sterilize the cervix. Then, a thin, flexible catheter is used to deliver contrast dye through the cervix and into the uterus. The speculum is then removed, and fluoroscopy images are taken from outside the body to create a wide view of the uterus and fallopian tubes. Because HSG is typically not performed during menstruation, it’s usually scheduled 6 to 12 days after the onset of menstrual bleeding. Patients often experience cramping and/or spotting for one or two days after the procedure. If you’re planning an HSG, talk to your provider about the best way of managing pain during and after the exam.

Iowa Radiology provides a wide range of imaging services to meet patients’ needs. These include hysterosalpingography, sonohysterography, as well as many other X-ray, ultrasound, and MRI procedures. To learn more about how various types of imaging support effective health care, browse our blog or our free resource library.



Cleveland Clinic. Hydrosalpinx. November 11, 2022. Accessed December 1, 2023.

Keltz M, Brown EC, Frishman GN, et al. Fluoroscopically-Guided Hysteroscopic Tubal Cannulation: A Procedure for Proximal Tubal Obstruction. JSLS. 2022 Oct–Dec;26(4):e2022.00047.

Unlu BS, Yilmazer M, Koken G, et al. Comparison of four different pain relief methods during hysterosalpingography: a randomized controlled study. Pain Res Manag. 2015 Mar-Apr;20(2):107–11.

WebMD. What Fallopian Tube Procedures Help With Fertility? Medically reviewed August 11, 2022. Accessed December 1, 2023.

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