Things about the uterus It is a small muscular organ located in the small pelvis and is closely resembling a small pear. On average, the uterus is 4 × 3 cm in size and is 99% muscle. The body of the uterus is angled to the cervix, in other words, it may be bent upward (toward the bladder) or downward (toward the rectum). The uterus is a unique organ! Its structure allows the uterus to grow dozens of times during pregnancy and safely return to its former size after childbirth.