Normally the egg that is released by the ovary it is ‘caught’ by one of the fimbriae and transported along the fallopian tube to the uterus. Fertilization usually ocurrs in the tubes and then the developing embryo implants in the uterus about one week after ovulation. When the egg is fertilized and cultured outside the body, this is called In Vitro Fertilization (IVF). The most common reasons for IVF are: