What is an HSG test and why is it done in a fertility evaluation?
A hysterosalpingogram — the HSG — is an X-ray procedure in which a small amount of contrast dye is introduced through the cervix into the uterine cavity. As the dye flows through, X-ray images show the shape of the uterine cavity and whether the dye spills freely through both fallopian tubes into the pelvis. If it does, the tubes are open. If it does not, the tube is blocked at the point where the dye stops. Its alternative, the sonosalpingogram (SSG), achieves the same purpose using ultrasound guidance rather than X-ray.
The investigation is a routine and essential part of the fertility evaluation because fallopian tube blockage is one of the most common causes of infertility — it prevents the egg and sperm from meeting and can result from previous infection, pelvic inflammatory disease, endometriosis, or prior surgery.
The HSG also provides information about the uterine cavity itself. Abnormalities such as a uterine septum, submucous fibroid, or polyp can be identified — all of which can interfere with implantation and pregnancy maintenance.
Open tubes with a normal cavity: No tubal or uterine factor contributing to infertility — further investigation focuses elsewhere
Unilateral blockage (one tube blocked): Conception may still be possible through the open tube, depending on other factors
Bilateral blockage (both tubes blocked): Natural conception is not possible — IVF, which bypasses the tubes entirely, becomes the appropriate treatment pathway
Uterine cavity abnormality identified: Further investigation or hysteroscopy may be recommended before proceeding with treatment
The HSG is typically performed in the first half of the menstrual cycle, after bleeding has stopped and before ovulation. It takes approximately fifteen to thirty minutes and may cause brief cramping. The information it provides is fundamental to planning the right treatment for each couple at Birthright Fertility, Banjara Hills, Hyderabad.
Written by Dr Sudharani Bairraju, MBBS (Sri Venkateswara Medical College, Tirupathi, 1997), DNB Obstetrics and Gynaecology (St Theresa's General Hospital, Hyderabad, 2007), Postgraduate Certification in Clinical Embryology, Fellowship in Minimally Invasive Surgeries, Fellowship in Advanced Gynaecological Endoscopy, Senior Consultant Obstetrician and Gynaecologist, Infertility (IVF) Specialist and Laparoscopic Surgeon, Birthright Fertility by Rainbow Hospitals, Banjara Hills, Hyderabad.