Normal Range of Uterine Size

During gynecological B-mode ultrasound examinations, the diagnostic report invariably lists the size of the uterus. The uterus is a predominantly muscular organ shaped like an inverted, slightly flattened pear. It lies centrally within the pelvic cavity of the lower abdomen, positioned between the bladder and the rectum, and consists of four parts: the uterine fundus, corpus (body), isthmus, and cervix. So, what constitutes the normal size range for the uterus?

Under normal circumstances, the sum of the uterus’s length, thickness, and width exceeds 12 cm. Specifically, its length measures 5.5–7.5 cm, its width 4.5–5.5 cm, and its thickness 3–4 cm. To assess uterine size, a gynecological examination can be performed during the non-menstrual phase.

Uterine hypoplasia (incomplete or underdevelopment) may impair fertility. A small uterus reflects delayed uterine development—failure to reach normal size—and thus inevitably affects female fertility to some degree; in severe cases, it may lead to uterine infertility.

Uterine size varies across different stages of female development. In adult women, the uterus may gradually enlarge with advancing age, but subsequently shrinks after menopause. Slight deviations—either larger or smaller than the normal range—typically have no significant impact on fertility. Additionally, ultrasound reports often describe the ratio of the uterine body to the cervix: this ratio is 1:2 in infancy and 2:1 in adult women.