Levator-urethra gap: is there a need for individualization of cut-offs?

To determine whether height, weight and body mass index (BMI) are associated with the levator-urethra gap (LUG) measurement, and whether these factors confound the relationship between LUG and symptoms and signs of pelvic organ prolapse (POP).

This was a retrospective study of women seen at a tertiary urogynecology unit between January 2020 and December 2021. Postprocessing of saved ultrasound volume data was used to measure the LUG, blinded against all other data. This measurement was tested for its association with organ descent and hiatal area, and height, weight and BMI were investigated for any potential confounding effect.

The 624 women seen during the inclusion period presented mostly with stress urinary incontinence (448/624 (72%)), urgency urinary incontinence (469/624 (75%)) and/or prolapse (338/624 (54%)). Mean age at assessment was 58 (range, 20-94) years, mean height was 163 (range, 142-182) cm, mean weight was 80 (range, 41-153) kg and mean BMI was 30 (range, 17-65) kg/m². LUG measurements could be obtained in 613 women, resulting in 7356 (12 × 613) measurements. The average LUG in individual women measured 2.35 cm on the right and 2.32 cm on the left side (difference not significant), with a mean ± SD of 2.34 ± 0.63 cm overall. Mean LUG was associated with symptoms and signs of prolapse, both on clinical examination (POP quantification system) and on imaging, but not with height (P = 0.36), weight (P = 0.20) or BMI (P = 0.09).

Levator-urethra gap measurements do not seem to be significantly associated with height, weight or BMI in our population, obviating the need for individualization of LUG. However, this does not exclude interethnic variability of this biometric measure. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.