Objective: We tested the null hypothesis that vesical neck descent is the same during a cough and during a Valsalva maneuver. We also tested the secondary null hypothesis that differences in vesical neck mobility would be independent of parity and continence status.

Methods: Three groups were included: 17 nulliparous continent (31.3 +/- 5.6; range 22-42 years), 18 primiparous continent (30.4 +/- 4.3; 24-43), and 23 primiparous stress-incontinent (31.9 +/- 3.9; 25-38) women. Measures of vesical neck position at rest and during displacement were obtained by ultrasound. Abdominal pressures were recorded simultaneously using an intravaginal microtransducer catheter. To control for differing abdominal pressures, the stiffness of the vesical neck support was calculated by dividing the pressure exerted during a particular effort by the urethral descent during that effort.

Results: The primiparous stress-incontinent women displayed similar vesical neck mobility during a cough effort and during a Valsalva maneuver (13.8 mm compared with 14.8 mm; P =.49). The nulliparous continent women (8.2 mm compared with 12.4 mm; P =. 001) and the primiparous continent women (9.9 mm compared with 14.5 mm; P =.002) displayed less mobility during a cough than during a Valsalva maneuver despite greater abdominal pressure during cough. The nulliparas displayed greater pelvic floor stiffness during a cough compared with the continent and incontinent primiparas (22.7, 15.5, 12.2 cm H(2)O/mm, respectively; P =.001).

Conclusion: There are quantifiable differences in vesical neck mobility during a cough and Valsalva maneuver in continent women. This difference is lost in the primiparous stress-incontinent women.