HSG stands for hysterosalpingogram, an X-ray procedure used to examine the uterus and fallopian tubes, often during fertility evaluations.
If you’ve been trying to conceive for a while and your doctor mentions an HSG, you might wonder what those three letters actually mean. The term sounds clinical and maybe a little intimidating, but it’s simply shorthand for a common diagnostic test.
HSG stands for hysterosalpingogram — a low-dose X-ray that uses contrast dye to give your doctor a clear picture of your uterine cavity and fallopian tubes. It’s one of the first tests many fertility specialists recommend when they need to check whether the tubes are open and the uterus has a normal shape.
What Exactly Is an HSG?
A hysterosalpingogram (HSG) is a fluoroscopic X-ray procedure. That means it uses a special low-exposure form of X-ray that streams real-time images to a monitor. The radiologist watches the dye as it moves through your reproductive tract.
Contrast dye enters the uterus through a thin catheter placed in the cervix. The dye fills the uterine cavity and then flows into the fallopian tubes. If the tubes are open, the dye eventually spills into the abdominal cavity.
The entire exam takes about 15 to 30 minutes. Because it uses low-dose X-ray, partners are not allowed in the room for safety reasons. You can eat and drink normally before the test.
Why Doctors Recommend This Fertility Test
When you’re in the middle of an infertility workup, bloodwork and ovulation kits aren’t enough to find the full picture. An HSG answers specific structural questions that other tests can’t see.
- Check for blocked fallopian tubes. Blocked tubes prevent the egg and sperm from meeting. HSG is the standard way to confirm whether your tubes are patent (open).
- Assess uterine shape. Fibroids, polyps, or a septum can affect implantation. The HSG outlines the contour of the uterine cavity.
- Part of the infertility evaluation. ACOG notes that HSG is a routine part of the initial fertility workup for many women.
- Rule out uterine abnormalities. An abnormal shape can lead to recurrent pregnancy loss. The test helps identify issues that might need surgical correction.
Most women get an HSG after about a year of trying to conceive without success. Some doctors order it sooner if you have known risk factors like a history of pelvic infection or previous tubal surgery.
What HSG Reveals About Your Uterus and Tubes
The power of an HSG lies in what it can see. It shows whether your fallopian tubes are open and whether the uterine cavity has a normal shape. The procedure itself uses fluoroscopy, a form of low-dose X-ray that, as the fluoroscopic hysterosalpingography page at UCSF describes, minimizes radiation exposure while providing real-time imaging.
In addition to patency, the dye pattern can reveal uterine abnormalities like a T-shaped uterus, adhesions from scar tissue, or polyps. If the dye does not pass through one or both tubes, that suggests a blockage. The test also gives a general sense of the internal environment — a healthy uterine cavity appears smooth and regular.
HSG is not designed to evaluate the ovaries or the outer parts of the tubes. It focuses on the inner surfaces, which is why it pairs well with other imaging tests like ultrasound or sonohysterography when a full picture is needed.
| What HSG Checks | What It Looks For | Normal Finding |
|---|---|---|
| Fallopian tube patency | Blockages or scar tissue | Dye spills freely into abdominal cavity |
| Uterine cavity shape | Fibroids, polyps, septum, adhesions | Smooth, regular contour |
| Internal structure | T-shaped uterus or congenital anomalies | Normal triangular shape |
| Dye flow pattern | Asymmetry or slow filling | Symmetrical, even flow |
| Post-procedure spill | Confirms tubes are open | Contrast seen around bowel and ovaries |
Keep in mind that HSG is a structural test. It won’t tell you anything about hormonal issues, egg quality, or sperm function. It focuses on the plumbing — the passageways that need to be clear for conception to occur.
What to Expect During the HSG Procedure
The anticipation can make you nervous, but knowing the steps ahead of time helps. Most women describe the HSG as uncomfortable rather than intensely painful — cramping is common as the dye fills the uterus.
- Positioning on the table. You lie on your back with your knees bent and feet supported on footrests, just like a routine gynecologic exam.
- Speculum insertion. The radiologist inserts a speculum to hold the vaginal walls apart, then cleans the cervix.
- Catheter placement. A thin, flexible catheter is guided through the cervix into the uterus. This may cause mild pressure or a pinch.
- Dye injection. The contrast dye is slowly injected while the radiologist takes X-ray images. You may feel cramping or warmth as the dye moves.
- Image review. The doctor watches the real-time fluoroscopic images and may take a few still pictures before removing the catheter.
The whole thing wraps up in under half an hour. You can go home right after and resume normal activities, though some women prefer to take it easy for the rest of the day. Cramping usually fades within a few hours.
Understanding Your HSG Results
Your doctor will typically go over the initial findings right after the test, but a full report takes a day or two. The key result is whether the dye passed through both fallopian tubes into the abdominal cavity. If it did, your tubes are considered patent. Mayo Clinic explains the basics of this test in their HSG overview, noting it helps confirm open tubes and a normal uterine cavity.
If one or both tubes are blocked, that doesn’t necessarily mean you can’t conceive — it just guides your next steps. Sometimes a blockage is temporary from mucus or muscle spasm, and a repeat test or a laparoscopy can clarify. Other times the blockage is due to scar tissue, infection, or endometriosis.
The uterine shape shown on the HSG can suggest whether any abnormalities might affect implantation. A suboptimal contour may prompt further evaluation with saline-infusion sonography or hysteroscopy. Most abnormal findings are treatable.
| Possible Result | What It Suggests |
|---|---|
| Dye spills from both tubes | Tubes are open; normal finding |
| Dye spills from only one tube | One side may be blocked or spasming |
| No spill from either tube | Both tubes likely blocked (proximal or distal) |
| Irregular uterine filling | Possible fibroid, polyp, or adhesion |
The Bottom Line
HSG is a safe, quick outpatient exam that gives your fertility team crucial information about your fallopian tubes and uterine cavity. It’s often one of the earliest tests in the workup because the results can change your treatment plan significantly — from proceeding with timed intercourse to considering surgery or IVF.
If you’re scheduled for an HSG, your reproductive endocrinologist or gynecologist will let you know exactly how it fits into your broader fertility evaluation and whether your specific cycle timing and any pre-existing conditions need special consideration.
References & Sources
- Ucsf. “Hysterosalpingogram Hsg Procedure” HSG uses a special form of low-dose X-ray called fluoroscopy to examine the uterus and fallopian tubes.
- Mayo Clinic. “Hsg Test” HSG stands for hysterosalpingogram (or hysterosalpingography), an X-ray procedure that outlines the internal shape of the uterus and shows whether the fallopian tubes are blocked.