Decrease in urethral pressure following repeated cough efforts: a new concept for pathophysiology of stress urinary incontinence.

AIMS: To describe the decrease in maximum urethral closure pressure (MUCP) following repeated coughs in women with stress urinary incontinence (SUI).

METHODS

MUCP was recorded at rest and after seven cough efforts in 70 women under age 40 referred for urodynamic investigation (47 women with SUI and 23 women without SUI).

RESULTS

The intraclass correlation coefficient for repeatability was very good at 400 mL filling volume: 0.94 (95%CI: 0.85-0.98), as compared to the mean and standard-deviations of the MUCP measurements. A decrease in MUCP >20% after seven cough efforts was observed in 18(38%) patients in the SUI group and in just 1(4%) woman in the non-SUI group (P = 0.0069).

CONCLUSIONS

Many women with SUI exhibit a sharp decrease in MUCP after repeated coughs. Many hypotheses may explain this phenomenon, including increased fatigue of the periurethral muscles.