Tubal patency tests are medical tests done to find out if the fallopian tubes are blocked. Completely blocked tubes cause infertility because the sperm are unable to reach the egg to fertilize it. However, if the tubes are damaged and not completely blocked, the sperm may be able to reach the egg but the early embryo is more likely to be trapped in the fallopian tube, leading to a dangerous condition of ectopic pregnancy. Tests for tubal patency can only be done by trained doctors.
Attribution: Straight Talk Foundation