HSG Test for Fertility: What to Expect from HSG, SIS, and Office Hysteroscopy
What to expect from an HSG test, saline sonogram, and office hysteroscopy — how to prepare, what the pain is really like, and what the results mean.
HSG and saline sonogram are two of the most commonly ordered uterine tests in a fertility workup. The online horror stories aren't random — pain varies significantly — but knowing what each test does and how to prepare changes the experience. Here's what actually happens, and what the results tell your care team.
What is an HSG test and what does it show?
An HSG (hysterosalpingogram) is an X-ray procedure in which contrast dye is injected through the cervix. Its primary purpose is to check whether your fallopian tubes are open (patent). It also shows the overall shape of the uterine cavity. The procedure takes 10 to 15 minutes and is done in an office or radiology setting.
How painful is an HSG?
Pain varies enormously — this is the honest part. Some people describe it as a bad cramp; others describe it as one of the worst pains of their life. A blocked or partially blocked tube makes the HSG more painful because the dye has nowhere to go. Taking ibuprofen 600 to 800 mg 30 to 60 minutes beforehand is standard preparation. Bringing a heating pad and having someone drive you home are both reasonable precautions. If you know you're pain-sensitive, ask your clinic about stronger options — some offer a cervical block or light sedation.
What is a saline sonogram (SIS) and when is it ordered?
A saline infusion sonogram (SIS), also called a saline sonogram or sono-HSG, uses ultrasound with saline injected through the cervix. Its primary purpose is to evaluate the uterine cavity for polyps, fibroids, and scar tissue. It does not reliably assess the fallopian tubes. Like an HSG, it takes 10 to 15 minutes and is office-based. Your RE may order both: HSG first for tubal patency, with SIS added if the uterine cavity needs more detail.
What is an office hysteroscopy used for?
Office hysteroscopy is a third option some clinics offer. A small flexible scope passes through the cervix to directly visualize the uterine cavity — no X-ray, no saline infusion, and no anesthesia required. It is typically the least uncomfortable of the three procedures, and polyps can often be removed in the same visit.
What does it mean if your fallopian tubes are blocked on an HSG?
The HSG's primary purpose is to show whether dye passes freely through the fallopian tubes. If one or both tubes appear blocked, your RE will interpret the result in context — spasm during the procedure can occasionally mimic a blockage, and some findings warrant further evaluation before drawing clinical conclusions. What a blocked result means for your path forward is a conversation for your RE based on your full clinical picture.
How do you prepare for an HSG?
HSG is typically scheduled after your period ends and before ovulation — roughly cycle days 6 to 12. You will likely be asked to use contraception that cycle or abstain after cycle day 1. Many clinics prescribe a prophylactic antibiotic such as doxycycline beforehand. Empty your bladder right before the procedure. Wear something easy to change out of. Expect possible spotting or mild cramping for a day or two after — wear a pad. Call your clinic if you develop fever, heavy bleeding, or severe worsening pain.
What is the difference between an HSG and a saline infusion sonogram?
The key difference is what each test is designed to evaluate and how it does so. An HSG uses X-ray and contrast dye and is best for assessing tubal patency — whether the tubes are open. A saline infusion sonogram uses ultrasound and saline and is best for evaluating the uterine cavity for structural abnormalities like polyps, fibroids, or scar tissue. They answer different clinical questions, and your RE may order one or both depending on what they are looking for.