Intravaginal pressure generated during voluntary pelvic floor muscle contractions and during coughing: the effect of age and continence status.

Aims: The purpose of this study was to determine if, compared to continent women, women with stress urinary incontinence (SUI) generate lower intravaginal pressure (IVP) during maximum voluntary pelvic floor muscle contractions (PFM MVCs) or coughing, slower contraction times or less ability to sustain IVP, and if there are reductions in the ability to generate IVP during these tasks associated with increasing age.

Methods: Eighty-seven (35 continent, 35 with mild SUI and 17 with severe SUI) women participated. IVP data were acquired while participants performed PFM MVCs, maximum effort coughs and a sustained PFM contraction. The maximum IVP amplitudes measured during the MVCs and coughs, the time for IVP to reach a peak during coughing and the time for the IVP to drop by 50% during the sustained contraction were compared among the groups using separate analyses of covariance, with age included as a covariate.

Results: There were no differences in maximum PFM MVC IVP or in endurance time among the groups. Women with SUI produced higher cough IVP amplitudes than continent women. Age was associated with a reduction in IVP and with longer contraction times during coughing.

Conclusions: The data suggest that PFM weakness may not be an important factor in the pathophysiology of SUI. Women with SUI may intuitively use their PFMs to compensate for urethral sphincter or fascial deficits. The IVP generated during coughing and the speed at which peak IVP is attained are, however, substantially reduced with increasing age, which might affect continence in older women.