How to Determine the Normal Values for Anteverted and Retroverted Uterus

The position of a woman’s uterus can be determined directly via pelvic color Doppler ultrasound or transvaginal color Doppler ultrasound, or indirectly through gynecological bimanual or trimanual examination by palpating the abdomen.

In clinical practice, the normal uterine dimensions are approximately 7–8 cm in length, 4–5 cm in width, and 2–3 cm in thickness, with a uterine cavity capacity of about 5 mL. Whether the uterus is anteverted, retroverted, horizontal, anteverted and anteflexed, or retroverted and retroflexed, its size remains within this normal range.

Within the pelvis, the uterus may be classified as anteverted (anterior position), mid-positioned, or retroverted (posterior position). Under normal circumstances, the uterus assumes an anteverted and anteflexed position. “Anteversion” refers to the entire uterine body tilting forward, while “anteflexion” denotes an angle of less than 90 degrees between the longitudinal axis of the uterine body and that of the cervix and vagina.

When the uterine body tilts backward toward the rectum, it is termed a retroverted uterus. Retroversion includes two subtypes: simple retroversion and retroversion with retroflexion. In simple retroversion, the longitudinal axis of the uterus remains unchanged while the entire uterus tilts posteriorly. In retroversion with retroflexion, the uterine body bends sharply backward at the junction between the corpus and cervix, forming an acute angle. The former is more common, whereas the latter is relatively rare. Common causes include ligamentous laxity and injury to the pelvic floor diaphragm and the base of the broad ligament following multiple vaginal deliveries.

Generally speaking, an anteverted uterus is associated with a higher risk of placenta previa; however, as the anatomically normal position, it confers relatively better fertility potential compared to a retroverted uterus.