How to Prepare for a Hysterosalpingography (HSG) Test

Preparing for a hysterosalpingography, commonly called an HSG, mostly comes down to scheduling it at the right point in your menstrual cycle, taking a pain reliever beforehand, and making sure your doctor knows about any relevant medical history like pelvic infections or allergies to contrast dye. The test itself takes roughly ten to fifteen minutes and involves pushing a contrast medium through your uterus and fallopian tubes so they show up on X-ray, but the preparation you do in the days and hours before can meaningfully affect how comfortable the experience is and how smoothly it goes.

Get the Timing Right

HSG is typically scheduled during the first half of your menstrual cycle, after your period has stopped but before ovulation. Most clinics aim for days 8 through 12 of your cycle, counting day 1 as the first day of your period.¹ This window exists for two reasons: the uterine lining is still relatively thin after menstruation, giving clearer images, and the chance of an early undetected pregnancy is lowest during this phase.

If your periods are irregular, let the scheduling staff know. They may ask you to call on the first day of your next period so they can count forward and book the appointment in the right window. Some clinics will still proceed outside that ideal window if your doctor considers the clinical need urgent, but this is the exception. If your period arrives late or the appointment falls on an awkward cycle day, call ahead rather than just showing up.

Expect a Pregnancy Test at the Door

Because the procedure involves X-ray radiation directed at your pelvis, clinics screen for pregnancy before proceeding. At many facilities, you will be asked to provide a urine sample for a quick pregnancy test when you arrive, even if you are confident you are not pregnant. This is standard safety protocol, not a reflection of doubt about your history. The test takes just minutes and is inexpensive.¹ Multi-institutional screening protocols have been adopted precisely because unsuspected pregnancies, while uncommon, do occasionally turn up.²

Take a Pain Reliever Before You Go

An HSG can be uncomfortable. The most commonly reported pain comes when the contrast dye is injected through the cervix and distends the uterine cavity, and again if the dye pushes through the fallopian tubes. Pain levels vary widely from person to person, but in studies comparing interventions, women who received no pain relief reported mean pain scores around 7 out of 10, while those given an oral anti-inflammatory beforehand scored closer to 4 or 5.³ That is a meaningful difference.

Most clinics recommend taking an over-the-counter nonsteroidal anti-inflammatory drug (an NSAID like ibuprofen) about 30 to 60 minutes before your appointment. One trial found that combining oral diclofenac (a prescription-strength NSAID) with a lidocaine cream applied to the cervix roughly halved pain scores during dye injection compared to placebo.⁴ Ask your doctor whether they plan to use any local anesthetic at the cervix during the procedure. Topical lidocaine spray has also been shown to reduce pain during HSG.⁵ If your clinic does not routinely offer it, asking about it is reasonable.

One thing worth knowing: pain during HSG sometimes relates to what the test is finding. If dye flows freely through open tubes, the procedure tends to be less painful than when it encounters a blockage or has to push past resistance. So the level of discomfort you experience is not entirely predictable in advance, and taking pain medication beforehand is a good hedge regardless.

Tell Your Doctor About Pelvic Infections or Dilated Tubes

If you have a history of pelvic inflammatory disease (PID) or your imaging has previously shown dilated fallopian tubes (a sign of prior infection), your doctor should know before scheduling the HSG. These conditions place you at higher risk for developing a pelvic infection after the procedure. A systematic review of antibiotic prophylaxis for transcervical procedures found that patients with a history of PID or dilated tubes are considered high-risk and should receive prophylactic antibiotics before HSG.⁶

For patients without those risk factors, routine antibiotic prophylaxis is generally not needed, though some doctors prescribe it anyway as a precaution. Some clinics also screen for sexually transmitted infections like chlamydia before the procedure, since pushing dye through the cervix could theoretically spread an active cervical infection upward. If you have not been tested for STIs recently and your clinic does not mention it, bring it up.

Post-procedure infections are uncommon overall, but in one older study of patients with dilated tubes, about 3% developed fever and pelvic inflammation requiring hospitalization within 24 hours.⁷ That number is specific to a high-risk population; the rate in women without prior tubal damage is much lower. Still, knowing to watch for fever, worsening pelvic pain, or unusual discharge in the days following the test is part of being prepared.

Mention Any Contrast or Iodine Allergies

HSG uses iodine-based contrast dye, either an oil-based or a water-based formulation. If you have ever had an allergic reaction to contrast dye used in a CT scan, a prior HSG, or any other imaging procedure, tell the team well before your appointment, not the day of. Current guidelines from the European Society of Urogenital Radiology note that for patients with prior hypersensitivity reactions, switching to an alternative contrast medium is now the preferred strategy over premedication with steroids or antihistamines.⁸ In other words, the approach has shifted toward finding a dye your body tolerates rather than loading you with drugs to mask the reaction.

A shellfish allergy, despite popular belief, does not reliably predict iodine contrast allergy. But any allergy history involving contrast agents is genuinely relevant and should be disclosed early so the team can plan accordingly.

Oil-Based Versus Water-Based Contrast and Why It Matters for You

You may not get to choose your contrast type, but it is worth understanding the difference because it can affect what happens after the test. A large randomized trial found that women who had their HSG performed with oil-based contrast had a significantly higher rate of ongoing pregnancy in the months following: about 40% compared to 29% with water-based contrast.⁹ Follow-up data at five years still showed an advantage, with more pregnancies conceived naturally in the oil-based group and a shorter time to pregnancy on average.¹⁰

Nobody is entirely sure why oil-based contrast seems to help. The leading theories include a possible flushing effect that clears debris or mucus from the tubes, and a potential immunological effect of the oil on the uterine lining.¹¹ Interestingly, the fertility benefit appeared strongest in women who experienced more pain during the procedure, which may point to a mechanical clearing mechanism at work in partially obstructed tubes.

There is a catch, though. Oil-based contrast contains iodine that is absorbed by the body more slowly, which can temporarily affect thyroid function. European guidelines now recommend testing thyroid function before an HSG using oil-based contrast and monitoring it for six months afterward.¹² If you have a thyroid condition, this is something to discuss with your doctor before the test. Water-based contrast clears the body faster and does not carry the same thyroid concern, so the choice between the two sometimes depends on your medical history as much as your fertility goals.

Mental Preparation Is Not Just Fluff

It is easy to dismiss advice about “staying calm” as vague and unhelpful when you are nervous about a medical procedure. But randomized trials have actually tested whether structured education and counseling before HSG make a measurable difference, and the answer is yes. Women who received pre-procedure education and counseling reported significantly less pain and anxiety than those who did not.¹³ Another trial testing a specialized preparation program found that pain levels immediately after the HSG and 30 minutes later dropped significantly in the group that received training, even though both groups started with similar pain expectations beforehand.¹⁴

A systematic review of non-drug approaches found that several strategies helped, including educational counseling, technology-based distraction techniques, and even acupressure-based warming therapy combined with music.¹⁵ The practical takeaway: learning what will happen step by step before you walk in genuinely reduces the pain you feel. Reading this article counts. Watching a video walkthrough of the procedure, asking your clinic for a printed handout, or talking through the steps with your doctor at a prior appointment are all versions of the same thing. The less your body is braced against the unknown, the less discomfort you tend to experience.

Radiation Exposure During HSG

Because HSG uses fluoroscopy (real-time X-ray), you will receive a small dose of radiation to your pelvic area. The dose from a standard HSG has been measured at roughly 1.2 mSv of effective dose, with the ovarian dose at about 2.7 mGy.¹⁶ For context, this is comparable to a few months of natural background radiation. The estimated risk of causing a genetic anomaly in a future embryo, or of inducing a fatal cancer in the patient, was calculated at less than one-thousandth of the baseline risk for either outcome.

Where exposure can climb is when the procedure takes longer than usual, requiring extended fluoroscopy time. A study comparing conventional HSG to rotational 3D-HSG found that the 3D technique delivered about fifteen times the radiation dose of the standard approach.¹⁷ If your facility uses 3D-HSG, it is worth asking about the added exposure and whether the diagnostic benefit justifies it for your case. For most patients undergoing a routine HSG, though, the radiation dose is low enough that it should not be a significant worry.

What to Do the Day Of

Most clinics will tell you that you can eat and drink normally before the test, since it does not require sedation or general anesthesia. A few practical steps can make the visit smoother:

Take your pain reliever on time: Ibuprofen or the NSAID your doctor recommended, about 30 to 60 minutes before the scheduled start. Do not skip it thinking you will tough it out.
Wear comfortable clothes: You will undress from the waist down, so a two-piece outfit is simpler than a dress.
Bring a pad: Some spotting and leaking of contrast fluid is normal afterward. A sanitary pad is more practical than a tampon for this.
Consider having someone drive you: While most women are fine to drive home, a small number experience vasovagal symptoms like dizziness, nausea, or lightheadedness during or shortly after the procedure.¹⁸ If you tend to feel faint during cervical procedures or blood draws, having a ride home is a smart precaution.

You can generally return to normal activity the same day. Some cramping and light spotting may continue for a day or two. If you develop a fever over 100.4°F (38°C), escalating pelvic pain, or foul-smelling discharge in the days following, contact your doctor promptly, as these could signal infection.

Alternatives Worth Knowing About

If the idea of radiation and iodine contrast concerns you, or if your doctor wants to assess tubal patency without a traditional HSG, there are alternatives. The most common is hysterosalpingo-foam sonography (HyFoSy), which uses ultrasound instead of X-ray and a foam contrast agent instead of iodine dye. HyFoSy avoids radiation entirely, can be done in a regular ultrasound room, and patients generally report less pain than with HSG.¹⁹

Diagnostic agreement between HyFoSy and HSG is moderate. Studies report complete concordance in roughly 73% to 85% of cases, meaning the two tests agreed on whether tubes were open or blocked.²⁰ However, HyFoSy appears to have a tendency to overestimate tubal patency, particularly in women with a retroverted uterus, and the two tests are not fully interchangeable.²¹ MR-based hysterosalpingography is another radiation-free option that has shown high accuracy for both tubal patency and uterine abnormalities, though it is less widely available and more expensive.²²

If you are being offered HSG specifically, though, it may be because your clinic uses oil-based contrast and wants the potential fertility-enhancing effect, or because your doctor wants the particular diagnostic clarity that fluoroscopy provides for evaluating uterine shape and tubal spillage patterns. The preparation steps described above apply exclusively to the traditional HSG; HyFoSy has its own, generally simpler preparation, which your ultrasound clinic can walk you through.

When HSG Gets Canceled or Rescheduled

A few situations can lead to your appointment being postponed on the spot. A positive pregnancy test is the most obvious one. Active vaginal bleeding, even light spotting at the end of your period, may prompt a reschedule because blood in the uterine cavity can mimic pathology on imaging. An active pelvic or vaginal infection is another reason to delay, as pushing contrast through an infected cervix raises the risk of spreading bacteria. If you arrive feeling unwell with a fever or suspect you may have an infection, mention it before the procedure starts rather than after.

Some women also get rescheduled because they arrived outside the correct cycle window. If your clinic is strict about days 8 through 12 and you are on day 15, they may ask you to come back next month. This can feel frustrating, especially when you have taken time off work, but the timing requirement exists to protect against both pregnancy exposure and suboptimal imaging quality. Keeping a simple period tracker in the weeks before your appointment can help you and the clinic land on a date that works.