The fallopian tubes, also known as oviducts, are the female reproductive organs that transport the ova from the ovary to the uterus each month. In the presence of sperm that later undergoes fertilization, the Fallopian tubes transport the fertilized egg to the uterus for implantation. If one or both Fallopian tubes are blocked, the egg cannot reach the uterus, and the sperm cannot reach the egg, preventing fertilization and pregnancy. It's also possible for the tube not to be blocked totally, but only partially. This can increase the risk of a ectopic pregnancy.