It has been claimed that urethral hypermobility and resting urethral pressure can largely explain stress incontinence in women. In this study we tried to replicate these findings in an unselected cohort of women seen for urodynamic testing, including as many potential confounders as possible.
This study is a retrospective analysis of data obtained from 341 women. They attended for urodynamic testing due to symptoms of pelvic floor dysfunction. We excluded from the analysis women with a history of previous anti-incontinence and prolapse surgery. All patients had a standardised clinical assessment, 4D transperineal pelvic floor ultrasound and multichannel urodynamic testing. Urodynamic stress incontinence (USI) was diagnosed by multichannel urodynamic testing. Its severity was subjectively graded as mild, moderate and severe. Candidate variables were: age, BMI, symptoms of prolapse, vaginal parity, significant prolapse (compartment-specific), levator avulsion, levator hiatal area, Oxford grading, midurethral mobility, maximum urethral pressure (MUP), maximum cough pressure and maximum Valsalva pressure reached.
On binary logistic regression, the following parameters were statistically significant in predicting urodynamic stress incontinence: age (P=0.03), significant rectocele (P=0.02), max. abdominal pressure reached (negatively, P<0.0001), midurethral mobility (P=0.0004) and MUP (negatively, P<0.0001). On multivariate analysis, accounting for multiple interdependencies, the following predictors remained significant: max. abdominal pressure reached (negatively, P<0.0001), cough pressure (P=0.006), midurethral mobility (P=0.003) and MUP (negatively, P<0.0001), giving an R2 of 0.24.
Mid-urethral mobility and MUP are the main predictors of USI. Demographic and clinical data are at best weak predictors. Our results suggest the presence of major unrecognised confounders.
European journal of obstetrics, gynecology, and reproductive biology 2015 Jul 31 [Epub ahead of print]
Edyta Wlaźlak, Grzegorz Surkont, Ka L Shek, Hans P Dietz
Clinic of Operative and Oncologic Gynecology, Medical University of Lodz, Wilenska 37, 94029 Lodz, Poland Electronic address: edytawlazlak@gmail com , Clinic of Operative and Oncologic Gynecology, Medical University of Lodz, Wilenska 37, 94029 Lodz, Poland , Sydney Medical School Nepean, University of Sydney, Nepean Hospital, Penrith, Sydney, NSW 2750, Australia , Sydney Medical School Nepean, University of Sydney, Nepean Hospital, Penrith, Sydney, NSW 2750, Australia