Normal HSG Results: Tubal Patency Test Explained (2026)

What does a normal hysterosalpingogram look like? HSG report results, bilateral tubal patency meaning, blocked tubes, and what each finding means for fertility.

A Hysterosalpingogram (HSG) is an X-ray procedure that evaluates the shape of your uterine cavity and whether your fallopian tubes are open (patent). It's one of the essential tests in a basic fertility workup, as blocked tubes or uterine abnormalities can prevent pregnancy.

What the HSG Shows

The HSG uses contrast dye and X-ray imaging to visualize:

  • Uterine cavity shape: Normal, bicornuate, septate, or other anomalies
  • Uterine abnormalities: Fibroids, polyps, adhesions (Asherman's syndrome)
  • Tubal patency: Whether tubes are open and dye flows through
  • Tubal abnormalities: Hydrosalpinx (fluid-filled blocked tube), proximal or distal blockage
  • Spillage: Dye flowing into abdominal cavity indicates open tubes

Understanding Normal Results

A normal HSG shows:

  • Smooth, triangular-shaped uterine cavity
  • No filling defects or abnormal shadows in the uterus
  • Dye flowing through both fallopian tubes
  • Free spillage of dye from the ends of both tubes into the pelvic cavity

Some studies show slightly higher pregnancy rates in the months following an HSG, possibly because the dye 'flushes' the tubes—this is called the 'therapeutic effect.'

Interpreting Tubal Blockage

Blocked tubes are described by location:

  • Proximal blockage: Near the uterus; may be spasm (false positive) or true blockage
  • Mid-tubal blockage: Middle of tube; often from prior infection or surgery
  • Distal blockage: At the end of tube; often with hydrosalpinx (fluid-filled tube)
  • Unilateral: One tube blocked; pregnancy possible through open tube
  • Bilateral: Both tubes blocked; IVF usually required

Proximal blockage on HSG can be a false positive due to tubal spasm. Your doctor may recommend a repeat HSG or selective catheterization to confirm.

Uterine Abnormalities on HSG

HSG can detect uterine issues that may affect implantation:

  • Filling defects: May indicate polyps, fibroids, or adhesions
  • Uterine septum: Wall dividing the uterine cavity
  • Bicornuate uterus: Heart-shaped uterus
  • T-shaped uterus: Associated with DES exposure
  • Asherman's syndrome: Scarring/adhesions from prior surgery

Next Steps After Abnormal HSG

If your HSG shows abnormalities, your doctor may recommend:

  • Hysteroscopy: Camera inserted into uterus to directly view and treat problems
  • Laparoscopy: Surgical evaluation and treatment of tubal issues
  • Repeat HSG: To confirm proximal blockage isn't spasm
  • Sonohysterogram (SHG): Saline-infusion ultrasound for clearer uterine view
  • Proceed to IVF: If bilateral tubal blockage confirmed

What to Expect During the Procedure

The HSG is typically performed in the first half of your cycle (after period, before ovulation). You may experience cramping during dye injection. Most women tolerate it well with over-the-counter pain relief. The procedure takes about 15-30 minutes.

Key takeaways

  • HSG evaluates uterine shape and whether fallopian tubes are open
  • 'Spill' of dye from tube ends indicates open, functional tubes
  • Proximal blockage may be spasm (false positive)—consider repeat testing
  • Bilateral tubal blockage typically requires IVF to conceive
  • Some women experience a 'fertility boost' in months following HSG

Frequently asked questions

Does HSG hurt?

Most women describe cramping similar to period pain during the procedure, especially when dye is injected. Taking ibuprofen an hour before can help. The discomfort typically lasts only minutes.

Can HSG open blocked tubes?

In some cases, the pressure of dye can open mildly blocked tubes or clear mucus plugs. This is why some studies show increased pregnancy rates after HSG. However, significant blockages require treatment.