In normal reproduction, the eggs pass through the fallopian tubes as they travel from the ovaries to the uterus. Simultaneously, sperm swim from the vagina through the cervix and uterus, entering the fallopian tubes to meet and fertilize the eggs. However, in women who have had pelvic infections or operations, the fallopian tubes can become blocked. In such cases, pregnancy may be achieved by surgically repairing the fallopian tubes or bypassing the tubes altogether with in vitro fertilization.
