Hysterosalpingography (HSG) is a specialized X-ray procedure used to visualize a woman’s reproductive anatomy. This test involves injecting a contrast material, typically a liquid containing iodine, into the uterine cavity through the cervix. As the dye flows, continuous X-rays (fluoroscopy) capture images. These images allow medical providers to assess the shape of the uterus and determine if the fallopian tubes are open. HSG is a quick, outpatient examination providing valuable information about the structural health of the reproductive tract.
The Critical Timing of the Procedure
The timing of an HSG within the menstrual cycle is a precise requirement for patient safety and clear diagnostic images. The procedure must be scheduled after the last day of menstrual bleeding but before ovulation occurs. This generally places the appointment between Day 6 and Day 12 of a standard 28-day cycle. Day 1 of the cycle is counted as the first day of full menstrual flow.
This narrow window is maintained primarily to eliminate the possibility of performing the procedure during an undetected, early pregnancy. Since the HSG involves X-rays and contrast dye, exposing a newly conceived embryo to these elements must be avoided. Therefore, the appointment is always set in the pre-ovulatory (follicular) phase of the cycle.
Scheduling the HSG during this specific time also optimizes the accuracy of the images obtained. Immediately following menstruation, the endometrial lining of the uterus is at its thinnest point. A thin lining ensures the contrast dye clearly outlines the internal structure of the uterine cavity. This prevents the lining from obscuring potential abnormalities or being mistaken for polyps or fibroids.
Performing the test after bleeding has fully stopped ensures that residual blood or tissue does not interfere with the flow of the contrast material. Obstruction from menstrual debris could lead to an inaccurate or inconclusive result, potentially indicating a false blockage in a fallopian tube. Patients are instructed to call the clinic on Day 1 of their cycle to secure an appointment within this designated timeframe.
Clinical Reasons for Ordering HSG
The most common reason a healthcare provider orders an HSG is to evaluate female infertility. When a couple has been trying to conceive for 6 to 12 months without success, this test investigates whether a physical obstruction is preventing pregnancy. The ability of the dye to flow freely through the fallopian tubes and spill into the pelvic cavity is the primary indicator of tubal patency.
Beyond assessing tubal blockage, the procedure offers information about the internal shape of the uterus. Structural issues within the uterine cavity, such as submucosal fibroids, endometrial polyps, or intrauterine scarring (synechiae), can contribute to difficulties with conception or recurrent pregnancy loss. The contrast material highlights these filling defects, providing a roadmap for potential surgical correction.
The HSG is also used to evaluate the success of certain gynecological procedures. For example, it confirms that fallopian tubes have been successfully reopened following a tubal reversal surgery. Conversely, it is utilized after a tubal sterilization procedure to confirm that the tubes are fully and permanently closed.
Essential Preparation and Screening
Preparation for an HSG begins before the appointment date and focuses on minimizing risk and discomfort. Because the procedure must be done before ovulation to avoid a potential pregnancy, patients must abstain from unprotected sexual intercourse from the first day of their menstrual period until after the HSG is complete. This step adheres to safety guidelines.
Many providers recommend taking a non-steroidal anti-inflammatory drug (NSAID) like ibuprofen 30 to 60 minutes before the scheduled procedure. This pre-emptive medication helps reduce the intensity of cramping experienced when the contrast dye is injected into the uterus. The cramping is often described as similar to moderate to severe menstrual pain.
A negative pregnancy test is a mandatory requirement, and most clinics administer a urine test on the day of the procedure to confirm this prerequisite. Patients with a history of pelvic inflammatory disease or other infection risk factors may be prescribed prophylactic antibiotics to take before and after the test. Patients must also notify the medical team of any known allergies, particularly to iodine or shellfish, as the contrast dye is typically iodine-based.
What to Expect During and Immediately After
The HSG procedure is performed in an outpatient setting, often in a radiology department, and typically takes less than 30 minutes. The patient is positioned on an X-ray table, similar to a standard gynecological exam. A speculum is gently inserted to visualize the cervix.
The provider cleanses the cervix and threads a thin, flexible catheter into the cervical opening and the uterus. The speculum is then removed. The iodinated contrast dye is slowly injected through the catheter into the uterine cavity. As the dye fills the uterus and flows into the fallopian tubes, the fluoroscopy unit captures real-time images.
During the injection of the dye, the patient may feel pressure and cramping. This sensation is generally temporary and subsides quickly once the procedure is complete. After the test, some contrast material will leak from the vagina. Patients should wear a sanitary pad, not a tampon.
Mild to moderate cramping and light vaginal spotting are common for a day or two following the procedure. Most individuals can resume their normal daily activities immediately. However, they should contact their doctor if they experience severe pain unrelieved by over-the-counter medication, heavy bleeding, or a fever, as these could indicate an infection.