A hysterosalpingogram is done mainly for women who are having a hard time becoming pregnant. Some studies show that this test may help a woman's chance of becoming pregnant because the dye may remove mucus plugs, straighten the fallopian tubes, and break through thin scar tissue.
Hysteroscopy may be done instead of a hysterosalpingogram to look at the uterus. Another test called laparoscopy may also be done instead of a hysterosalpingogram to look at the fallopian tubes. A laparoscopy does not show whether the fallopian tubes are open, unless dye is injected during the laparoscopy.
Another test, a sonohysterogram (SHG), may be more accurate than a hysterosalpingogram for looking at uterine fibroids or polyps. SHG uses ultrasound to watch the movement of a salt solution (saline) that is injected into the uterus. SHG does not use X-rays or an iodine dye.
If a blocked fallopian tube is the cause of infertility, an oil-based dye may be used during a hysterosalpingogram to remove the blockage. Some studies show that an oil-based dye may open up a blockage better than a water-based dye, but other studies have shown no difference between the two dyes.
Be sure your doctor knows if you take metformin (such as Glucophage) for diabetes or for any other reason, such as polycystic ovary syndrome (PCOS), because of the possible interaction with the dye used in this test.