What is abnormal uterine descent on translabial ultrasound?

Introduction and hypothesis: Ultrasound is increasingly used in evaluating women with pelvic floor dysfunction, including quantification of pelvic organ prolapse (POP). The aim of this study was to define the optimal cutoff for uterine descent on translabial ultrasound (TLUS) to predict symptoms of prolapse. Methods: This was a retrospective study of patients seen for lower urinary tract symptoms and/or POP at a tertiary urogynecological center. All patients underwent a standardized interview, 4D TLUS and the International Continence Society Pelvic Organ Prolapse Quantification system (ICS POP-Q) assessment. Pelvic organ descent on US was measured relative to the posteroinferior margin of the symphysis pubis (SP) on maximum Valsalva. Receiver operator characteristic (ROC) statistics was used to determine the optimal cutoff. Results: We assessed 538 data sets. Mean patient age was 53 years (range 18–88). Prolapse symptoms were reported by 263 (49 %). Clinically significant POP, i.e., ICS POP-Q stage ≥2 was found in 74.5 %. This comprised a cystocele in 322, uterine prolapse in 63, enterocele in ten, and rectocele in 280 women. On TLUS, mean uterine position on Valsalva was 14.3 mm above the SP. Prolapse symptoms were strongly associated with uterine descent (20.7 mm vs 7.6 mm, P < 0.001). Using ROC statistics with and without excluding women with a dominant prolapse in other compartments, +15 mm was found to be the optimal cutoff for predicting symptoms of prolapse, with areas under the curve of 0.68 and 0.74, respectively. Conclusions: An optimal cutoff to predict prolapse symptoms due to uterine descent is a cervix descending to 15 mm above the symphysis pubis on maximum Valsalva.