Department of Obstetrics and Gynecology, School of Nursing, University of Michigan, Ann Arbor, USA. janismm@umich.edu
OBJECTIVE: The purpose of this study was to determine if the ability to increase maximum urethral closure pressure (MUCP) with a pelvic muscle contraction is impaired in women without pubococcygeal muscle (PCM). STUDY DESIGN: This was a cross-sectional study of continent women comparing those with (n=28) and those without (n=17) PCM as identified by MR scans. A pelvic muscle contraction was performed simultaneously with recordings of urethral and bladder pressures. RESULTS: Eighty-six percent of the women with PCM compared with 41% of the women without could volitionally increase (>5 cm H(2)O) their MUCP. Those with PCM generated a mean intraurethral pressure rise of 14.0 (10.8) cm H(2)O, compared with 6.2 (8.7) cm H(2)O in those without (P=.015). Among women who could produce a visible pressure rise, there was not a statistically significant difference between groups (with PCM=17.2 [7.8] cm H(2)O; without PCM=14.7 [7.5] cm H(2)O; P=.457). CONCLUSION: Selective women without visible PCM can increase MUCP.