Function: The primary function of the uterus is in reproduction; the conduit for sperm transport, and the site for implantation of fertilized ova, placentation,  growth and development of the fetus, and parturition (labor and delivery).  The shape and position of the uterus also deflects downward-directed, intra-abdominal pressures anteriorly toward the pubis, away from the pelvic floor. The endometrium is a target tissue for estradiol from the ovarian follicles, creating a smooth cellular, proliferative lining for sperm transport prior to ovulation. Progesterone from the corpus luteum of the ovaries, which changes the lining to a thicker, softer, secretory lining for blastcyst implantation.