The normal size of the uterus is 7-8cm long, 4-8cm wide, 2-3cm thick and has a capacity of about 5ml. The uterus is an important organ for women to conceive a fetus and produce menstruation. The female uterus is divided into two parts, the body of the uterus and the cervix. The ratio of the body of the uterus to the cervix varies at different times, with 1:2 for pre-pubertal women, 2:1 for fertile women, and 1:1 for postmenopausal women; such a uterus is normal. The capacity of the uterus is about 5 ml in non-pregnancy and 5,000 ml in full-term pregnancy.The part of the uterus that connects the body of the uterus to the cervix is called the isthmus of the uterus, which is about 1 cm in length when a woman is not pregnant and 7-10 cm in the second trimester of pregnancy.