How to Determine the Normal Values for Anteverted and Retroverted Uterus
Jun 01, 2022
Source: Cainiu Health
Dr. Chong Yiwen
Introduction
Under normal circumstances, the uterus is in an anteverted and anteflexed position. “Anteversion” refers to the entire uterine body tilting forward. “Anteflexion” refers to the angle formed between the longitudinal axis of the uterine body and the longitudinal axis of the cervix and vagina being less than 90 degrees. When the longitudinal axis of the uterus remains unchanged but the entire uterus tilts posteriorly, it is termed “retroversion.”
The position of the uterus in females can be directly visualized using pelvic color Doppler ultrasound or transvaginal color Doppler ultrasound, or assessed by palpation during gynecological bimanual or trimanual examination.
Within the pelvis, the uterus may be classified as anteverted (anterior position), mid-positioned (mid-position), or retroverted (posterior position).
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 uterus tilts backward and forms an acute angle at the junction between the uterine body and cervix. Simple retroversion is more common, whereas retroversion with retroflexion 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 is associated with better fertility outcomes compared to a retroverted uterus.
