HSG Test (Hysterosalpingography) — How It Works, Benefits & Recovery — Procedure Guide, Recovery & Risks | MyMedicPlus

Hysterosalpingography (HSG) is a fluoroscopic X-ray procedure in which a water-soluble or oil-based iodinated contrast medium is injected through the cervix into the uterine cavity under real-time X-ray imaging to evaluate two critical aspects of female reproductive anatomy: the shape and internal contour of the uterine cavity, and the patency of the fallopian tubes. It is one of the oldest and most widely used diagnostic investigations in the fertility workup for women experiencing difficulty conceiving, having been in clinical use for over a century and remaining a first-line investigation in most international fertility guidelines including those of the American Society for Reproductive Medicine (ASRM) and the European Society of Human Reproduction and Embryology (ESHRE). HSG is performed by a radiologist in a fluoroscopy suite or by a gynaecologist in an interventional suite, and takes only 15–30 minutes as an outpatient procedure without general anaesthesia. Two contrast media types are in clinical use: water-soluble contrast provides rapid imaging and quicker excretion from the peritoneal cavity; oil-based contrast (Lipiodol) takes slightly longer but is associated with a well-documented therapeutic effect — multiple randomised controlled trials including the H2Oil trial (2017) demonstrated a 39.7% pregnancy rate in women receiving oil-based HSG versus 22.8% in those receiving water-based HSG, a difference attributed to mechanical tubal flushing, immune modulation, or disruption of mucous plugs. HSG is complementary to other investigations in the infertility workup including transvaginal ultrasound, ovarian reserve testing, and partner semen analysis.

HSG is a standard investigation for women presenting with primary infertility (never conceived) or secondary infertility (previously conceived but now unable to conceive) who have been trying for 12 months or more — or 6 months for women aged 35 and above, in line with current ESHRE and ASRM guidelines. It is also indicated for: women with a history of pelvic inflammatory disease (PID), which can cause tubal damage and adhesions; those with a prior ectopic pregnancy, which carries an elevated risk of the contralateral tube also being damaged; women with a history of abdominal or pelvic surgery that may have caused pelvic adhesions; patients with known or suspected Asherman syndrome (intrauterine adhesions from prior uterine surgery or infection); assessment of uterine cavity before intrauterine insemination (IUI) or in vitro fertilisation (IVF); evaluation for suspected congenital uterine anomalies such as septate, bicornuate, or unicornuate uterus that may cause recurrent miscarriage; and confirmation of successful bilateral tubal occlusion after surgical sterilisation or failed sterilisation reversal. The test is performed in the early follicular phase of the menstrual cycle (days 7–10 of a 28-day cycle) to avoid inadvertently imaging a newly conceived embryo and to ensure the endometrium is thin, providing the clearest cavity outline. Women with active pelvic infection, undiagnosed vaginal bleeding, or iodine contrast allergy require alternative investigation strategies.

The patient lies supine on a fluoroscopy table with knees bent (lithotomy position). A vaginal speculum is inserted to expose the cervix, which is cleaned with antiseptic solution. A small HSG catheter or metal cannula with a balloon tip is introduced through the cervical os and gently advanced into the uterine cavity; the balloon is inflated to 1.5–2 mL to create a seal at the internal cervical os and prevent contrast reflux. Patients taking ibuprofen 400–600 mg one hour before the procedure experience significantly less discomfort during balloon inflation and contrast injection. Iodinated contrast medium — water-soluble or oil-based as chosen by the clinician and patient in shared decision-making — is slowly injected under fluoroscopic control (real-time X-ray imaging) through the catheter while a radiologist or gynaecologist observes the contrast flow on a monitor. The uterine cavity fills first, outlining its triangular shape and internal contour; any filling defects representing submucous fibroids, endometrial polyps, or intrauterine adhesions are visible as negative shadows within the contrast-filled cavity. As injection continues, contrast passes through the tubal ostia (openings) and along each fallopian tube. Bilateral tubal patency is confirmed when contrast is seen spilling freely from the distal ends (fimbriae) of both tubes into the peritoneal cavity as a characteristic peritoneal spillage pattern. Tubal blockage at the cornual region (proximal occlusion) or mid-tube or distal (hydrosalpinx) is characterised by failure of contrast progression and varying degrees of tubal dilation. Between 3–6 fluoroscopic images or a short fluoroscopic video sequence is recorded. The catheter is removed and the patient observed for 15–30 minutes before discharge.

HSG accurately identifies tubal blockage with a sensitivity of 65–85% and specificity of 83–90% compared with laparoscopy with chromopertubation (the gold-standard reference test). It identifies uterine cavity abnormalities including submucous fibroids (appearing as filling defects), endometrial polyps, intrauterine adhesions (partial or complete synechiae producing irregular filling patterns), and congenital anomalies (uterine septum, bicornuate uterus, unicornuate uterus) with good diagnostic accuracy. The false-positive rate for tubal occlusion — normal tubes incorrectly reported as blocked — is 15–20%, most often due to tubal spasm at the cornu at the moment of dye injection; this resolves with relaxation or can be assessed by repeating the injection after a few minutes or by laparoscopic confirmation. A clinically important additional benefit of HSG — particularly with oil-based contrast — is a therapeutic flushing effect. The landmark multicentre H2Oil RCT (New England Journal of Medicine, 2017, n=1,119 women with unexplained infertility) demonstrated a significant improvement in ongoing pregnancy rate at 6 months: 39.7% after Lipiodol (oil-based) HSG versus 22.8% after water-based HSG and 29.1% in the no-treatment arm. This therapeutic benefit requires no additional intervention and represents a meaningful advantage of HSG as an investigation. HSG is rapid, widely available, cost-effective, and avoids the need for general anaesthesia required for laparoscopy.

HSG is generally a safe procedure. Uterine cramping during and immediately after contrast injection is the most common experience, similar in character to moderate menstrual pain, and is expected by most patients. The intensity varies from mild discomfort to more significant pain; pre-procedure analgesia (ibuprofen 400–600 mg orally or a paracervical block) significantly reduces discomfort. A vasovagal reaction — lightheadedness, bradycardia, pallor, or brief fainting — occurs in 3–5% of women, typically during cervical manipulation or balloon inflation, and resolves with rest and trendelenburg positioning. Pelvic infection is the most clinically serious complication. HSG can exacerbate subclinical or pre-existing pelvic infection or introduce organisms into the uterine cavity. Pelvic inflammatory disease (PID) post-HSG occurs in approximately 1–3% of all women, rising to 3–11% in women with prior tubal damage or hydrosalpinx. To mitigate this risk, prophylactic antibiotics — typically doxycycline 100 mg twice daily for 5 days — are prescribed when a dilated tube, pelvic adhesions, or prior PID history is identified. Iodine contrast allergy reactions range from mild urticaria (0.5–2%) to severe anaphylaxis (less than 0.01%) and are managed per standard contrast reaction protocols with pre-medication in known low-grade allergy cases. Uterine or tubal perforation by the catheter is very rare (under 0.1%) and usually self-limiting. Radiation exposure is very low — typically 3–7 mGy, equivalent to approximately 1 year of background radiation — and not a clinical concern in women of reproductive age.

Recovery from HSG is rapid. Uterine cramping during and immediately after the procedure is the most common experience, typically lasting 15–60 minutes and well-controlled with ibuprofen taken one hour before the test. Patients rest for 15–30 minutes after the procedure in the fluoroscopy suite. Most women drive home themselves and return to work the same day. Mild vaginal spotting or light bleeding from cervical manipulation may persist for 1–2 days and is normal. A light sanitary pad is worn for the day. A thin white discharge may occur over the following 1–3 days from contrast medium passing through the cervix — this is expected and not a sign of infection. Women who receive prophylactic antibiotics should complete the full course as prescribed. Signs of infection requiring immediate medical attention — new pelvic or lower abdominal pain, fever above 38°C, offensive discharge, or rigors in the 2–5 days following HSG — should prompt urgent clinical review, as post-procedure PID requires prompt antibiotic treatment. Normal sexual intercourse, swimming, and baths may resume after 24–48 hours. Cycle-specific ovulation timing is unaffected. A follow-up appointment with the fertility specialist to review HSG results and plan the next investigation or treatment step — whether hysteroscopy to address a uterine cavity abnormality, laparoscopy to confirm tubal status, or commencement of assisted reproductive treatment — is arranged within 2–4 weeks.