A blocked fallopian tube can happen sometimes during or after cervical surgery, if some blood and tissue go the wrong way up into the uterus. It can also happen due to an infection or even after having a baby. A specialist called a reproductive endocrinologist can detect this problem with a procedure called hysterosalpingogram, or HSG.
An HSG can also show if there is anything abnormal about your uterus, like fibroids or congenital deformities. Some women are born with a misshaped uterus, like two chambers instead of just one or only one fallopian tube instead of two.
During HSG, you are awake and lying on the table like for a pelvic exam. The doctor inserts a metal tube through the cervix and into the uterus, then injects dye to see if it spills out through the fallopian tubes into the abdomen. X-rays are taken during the injection, and you'll know right away if there is a blockage or not because they'll show you the X-rays.
If you have a blocked fallopian tube (or two), treatment may just require that the doctor goes in and clears it out laproscopically, or you may have to have one or more fallopian tubes removed.
Sometimes, if there is a blockage, the HSG blows it out during the injection. It may hurt as the dye first is blocked and then moves on through the tube. And the tube they put through your cervix is rather uncomfortable, too. Luckily, it's only about a 10 minute ordeal.
If your tubes are not blocked, it shouldn't hurt at all. The dye is absorbed into your system, and it comes out in your urine eventually.
HSG is done right after your period ends because it is important that you are not pregnant when the dye is injected. The reason is that if there were a fertilized embryo in your uterus, the dye could push it back into the tube or even into your abdomen. You don't want to end up with a tubal pregnancy or an abdominal pregnancy because those can't survive and have to be removed.
If your tubes are blocked and your doctor tries to clear them out under laproscopy, in the worst case scenario, you could lose both tubes.
This, however, doesn't mean you can't have children, but it does mean that you would have to go through in vitro fertilization, or IVF, to get pregnant. If you do have just one tube removed, you can still get pregnant naturally.