How common is it for someone to need a hysterosalpingography?

Very Common. Hysterosalpingography or hsg is still one of the first tests of infertility for all women. This test helps to determine whether the fallopain tubes are open and whether the uterine cavity is normal. Traditionally it is performed using x-rays and a contrast dye. Recently I have been using a new device (femvue) to inject saline with air bubbles and use ultrasound to determine if they are open.
Common. It is a very common test in the work up of infertility. It is excellent way to determine if the fallopian tubes are patent without a more invasive examination. It is important to know if the basic anatomy is intact if one is going to go through an entire fertility work up and decision regarding treatment options.
HSG Common? I agree with dr d. Let me add that hsg has bad reputation for being painful - not necessary with good technique. It is best for the tubes but only 50% as good as sis or hysteroscopy for uterine cavity (i often use the other techniques with hsg for complete picture). Hydrosalpinx very accurate (>90%) but adhesion diagnosis on 50%. Timing of test varies by your problem.
Routine test. We recoomend this test for all of our infertility work-ups as it helps assess the uterus and fallopian tubes. The tubes is where fertiliation takes place and the uterus is where an embryo implants. In next couple of years the hsg may go away. We are doing studies to use ultrasound to assess the tubes and cavity called sonosalpingography.