What are the indications for a hysterosalpingogram (HSG)?

Indications for Hysterosalpingography (HSG)

The primary indication for hysterosalpingography is the evaluation of female infertility, particularly to assess tubal patency and uterine cavity abnormalities. 1, 2

Primary Indications

• Evaluation of tubal patency: HSG allows detection of tubal patency, tubal size, tubal irregularity, and peritubal disease 1

  • Gold standard for evaluating tubal patency with a sensitivity of 65% and specificity of 85% compared to laparoscopy with chromopertubation 3
  • Can identify specific tubal abnormalities including:
    • Tubal occlusion
    • Hydrosalpinx
    • Salpingitis isthmica nodosum
    • Peritubal adhesions 4

• Assessment of uterine cavity abnormalities: HSG can detect various uterine abnormalities that may contribute to infertility 1, 4

  • Congenital uterine anomalies (though MRI is superior for classification)
  • Intrauterine synechiae (adhesions)
  • Endometrial polyps
  • Submucosal fibroids
  • Adenomyosis

• Post-operative evaluation:

  • Confirmation of tubal occlusion after sterilization procedures (e.g., Essure placement) 5
  • Pre-myomectomy evaluation 6

Secondary Indications

• Therapeutic benefit: Tubal flushing during HSG has been shown to increase pregnancy rates up to 38% compared to 21% in women who did not undergo HSG, with highest rates seen when oil-soluble contrast is used 1

• Recurrent pregnancy loss: Although HSG may provide useful information about the uterine cavity, it is not reliable in categorizing Müllerian duct anomalies and has been largely replaced by MRI and 3D ultrasound for assessment of the uterine cavity in recurrent pregnancy loss 1

Contraindications

• Active pelvic infection or recent PID
• Pregnancy or suspected pregnancy
• Recent uterine surgery
• Active uterine bleeding
• Iodine allergy (when iodinated contrast is used)

Clinical Considerations

• Timing: HSG should be performed in the follicular phase of the menstrual cycle (days 7-10) to:

  • Avoid potential pregnancy
  • Minimize risk of intravasation of contrast into venous system 5
  • Ensure better visualization (thinner endometrium)

• Antibiotic prophylaxis: Administration of prophylactic antibiotics is at the discretion of the referring physician, particularly if there is a prior history of PID or if hydrosalpinx is noted during the study 1

• Limitations:

  • Cannot always provide complete information about external uterine contour, limiting accurate distinction between septate and bicornuate uterus 1
  • Only 16.7% accurate in characterizing Müllerian duct anomalies compared to MRI (100% accurate) and 2D TVUS (92% accurate) 1

Alternative Diagnostic Modalities

• Hysterosalpingo-contrast sonography (HyCoSy): Alternative to HSG with 91% accuracy compared to laparoscopy 3

  • Can be performed as part of a comprehensive infertility examination along with 3D transvaginal ultrasound 1

• Hysteroscopy: Complementary to HSG, particularly for confirmation and treatment of intrauterine anomalies discovered by HSG 7

  • More accurate for characterizing the nature of intrauterine filling defects 7

• MRI: Superior for classification of Müllerian duct anomalies and assessment of external uterine contour 1

Remember that while HSG remains a valuable tool in the evaluation of infertility, it should be considered as part of a comprehensive approach that may include other imaging modalities based on specific clinical scenarios and findings.