Transabdominal Ultrasound Imaging of Pelvic Floor Muscle Activity in Women With and Without Stress Urinary Incontinence: A Case-Control Study

Objective: Transabdominal ultrasound (TAU) is an easy and noninvasive way to evaluate and retrain pelvic floor muscle (PFM) function. The purpose of this study was to compare PFM activity in women with and without urinary incontinence (UI) by measuring bladder base displacement (as a marker for PFM activity) using TAU during PFM contraction, Valsalva's maneuver, and abdominal curl. Methods: Sixty-three women, aged 20-55 years, volunteered to participate in this cross-sectional study: 21 were continent and 42 had UI (21 stress urinary incontinence [SUI] and 21 mixed urinary incontinence [MUI]). Mean bladder base displacement in millimeters was measured to evaluate differences between the three groups (continent, SUI, and MUI) and also between the continent and UI groups during the performance of each maneuver. Results: No significant differences were seen between the three groups in bladder base elevation during PFM contraction (P > 0.05). Descent of the bladder base during Valsalva's maneuver and abdominal curl was significantly greater in women with SUI and MUI than in women in the continent group (P < 0.05). Comparison of the continent and UI groups showed no significant differences in elevation of the bladder base during PFM contraction, while descent of the bladder base was significantly greater in women with UI than in women in the continent group during Valsalva's maneuver and abdominal curl (P < 0.05). Conclusion: TAU indicated that bladder base descent was greater in women with SUI and MUI than those in the continent group during the performance of maneuvers that increased intra-abdominal pressure. This effect may be due to decreased PFM performance in women with urinary incontinence. (C) 2020 The Society of Obstetricians and Gynaecologists of Canada/La Societe des obstetriciens et gynecologues du Canada. Published by Elsevier Inc. All rights reserved.