Tube, Fallopian: The two Fallopian tubes, one on each side, transport the egg from the ovary to the uterus (the womb). The Fallopian tubes have small hair-like projections called cilia on the cells of the lining.
These tubal cilia are essential to the movement of the egg through the tube into the uterus. If the tubal cilia are damaged by infection, the egg may not get 'pushed along' normally but may stay in the tube.
Infection can also cause partial or complete blockage of the tube with scar tissue, physically preventing the egg from getting to the uterus.
Any process (such as infection, endometriosis, tumors, or scar tissue in the pelvis (pelvic adhesions) that cause twisting or chinking of the tube) that damages the Fallopian tube or narrows its diameter increases the chance of an ectopic pregnancy: a pregnancy developing in the Fallopian tube or another abnormal location outside the uterus.