Is Uterus Anteverted or Retroverted?

53-year-old female with abdominal pain • Xray of the Week

53-year-old female presented with abdominal pain to the emergency department (ED). A non-contrast CT study was performed in prone position with suspicion of urinary system stone. No stone is appreciated in urinary system and no significant CT finding is found to explain the pain.

One month later patient presented with abdominal pain again to the ER. Contrast enhanced CT study ordered for evaluation. Routine postcontrast CT study is performed in supine position. The position of the uterus was different in supine and prone position CT study (Fig 1a-b).

Figure 1. a: Sagittal reconstruction of non-contrast (a) and post-contrast CT studies (b) which were performed at one-month intervals demonstrate anteverted position of the uterus in prone (yellow arrow) and retroverted position in supine position (orange arrow). White arrows indicate table position.

Discussion:

The uterus has a shape similar to an inverted pear. It is divided by body and cervix, and the superior part of the body above the entrance of the tuba uterine known as fundus. The uterus is a muscular organ located between the bladder anteriorly and the rectum posteriorly. It is also a mobile organ, since its position can vary depending on the contents of the bladder and rectum [1].

The tonus of the pelvic floor is the primary support for the uterus. Other ligaments that provide further support to the uterus include the broad ligament, round ligament, ovarian ligament, cardinal ligament, and the uterosacral ligament. The round ligament is composed of fibromuscular connective tissue. It is covered by folded peritoneum and comprises the superior margin of the broad ligament on each side of the uterus [2]. Two round ligaments extend from the uterine horns to the labia majora on each side via the inguinal canal and maintain the anteverted position of the uterus.

The most common position of the uterus is anteverted, with the cervix angled forward and anteflexed, and the body flexed anteriorly. A retroverted uterus is a normal variant seen approximately 20% of women where the body of the uterus is tilted posteriorly. There are variable degrees of uterine retroversion. The majority of the time, the retroverted uterus causes no symptoms; however, rarely it may be associated with dyspareunia and dysmenorrhea. This might be because the retroverted position causes the uterus to contact the rectum and posterior wall of the vagina. Mobilization of the uterus during intercourse may generate pain especially if the uterus is fixed in this position. The position of the uterus can also change during pregnancy. However, it is very uncommon for the uterus to switch positions in a normal subject such as seen in this case [3].

The mobility of the uterus can be attributed to the high flexibility of the round ligament. This flexibility might be due to its role in allowing the uterus to grow during pregnancy and adapting to the body’s shape. When a female is not pregnant, the round ligaments that support the uterus are often shorter and firmer. Yet, their flexibility allows them to lengthen, thicken, and stretch during pregnancy.

In the images above, we can readily see the difference in the position of the uterus in the prone and supine position. There are no CT findings in this case to explain the abdominal pain and it is uncertain if this uncommon mobility of the uterus is the reason.

References:

1. Tullington JE, Blecker N. Lower Genitourinary Trauma. In: StatPearls. Treasure Island (FL): StatPearls Publishing; May 22, 2020. Bookshelf ID: NBK557527

2. Chaudhry SR, Chaudhry K. Anatomy, Abdomen and Pelvis, Uterus Round Ligament. In: StatPearls. Treasure Island (FL): StatPearls Publishing; August 23, 2020. PMID: 29763145 Bookshelf ID: NBK499970.

3. Sanders RC, Parsons AK. Anteverted retroflexed uterus: a common consequence of cesarean delivery. AJR Am J Roentgenol. 2014;203(1):W117-W124. doi:10.2214/AJR.12.10403. PMID: 24951223.

Munevver N. Duran is a pre-medical undergraduate student at Rice University in Houston, Texas, currently double majoring in Kinesiology Sports Medicine and Religious Studies. Munevver was first exposed to radiologic imaging through her research and co-authorship to a review article about the additional diagnostic value of three-dimensional volume rendering imaging in Radiology practice. Her passion for radiology comes from the intersectionality of anatomy and physiology, diagnostic applications, and the continuously improving imaging technologies. In the future, she hopes to become a physician educator with a strong commitment to clinical research and patient-centered healthcare.

Ali Morshid is a diagnostic radiology resident at the University of Texas Medical Branch in Galveston, Texas. Ali grew very fond of medical imaging research and academic radiology during his work as a research assistant at MD Anderson Cancer Center and found great satisfaction in preparing didactic sessions and academic presentations for radiology trainees. Ali has multiple publications in peer-reviewed journals in the field of diagnostic radiology and he is working towards a fulfilling career as an academic neuroradiologist.