Factors Associated With Urinary Incontinence in Nulliparous Female Elite Athletes: An Exploratory, Cross-Sectional Study Using Dynamic Pelvic Magnetic Resonance Imaging and Questionnaire Data

Urinary incontinence (UI) is common in nulliparous female elite athletes, but underlying pathophysiology is inadequately understood. We examined urinary symptoms and associated pelvic floor anatomy and function in this population, hypothesizing that athletes with UI would exhibit pelvic floor findings seen in older incontinent women (e.g., pelvic floor descent and urethral hypermobility) and findings attributable to elite sporting such as muscle hypertrophy. We performed a cross-sectional study of NCAA Division 1 nulliparous female athletes comparing symptomatic (i.e. currently or previously experienced urinary leakage during exercise) and asymptomatic athletes. We assessed demographics, sport characteristics, relevant medical history (including Brief Eating Disorder in Athletes Questionnaire) and validated genitourinary symptom questionnaires (Lower Urinary Tract Dysfunction Network Symptom Index-29; Female Genitourinary Pain Index). Pelvic exam and dynamic MRI were used to assess the pelvic floor at rest and at maximal strain. Pelvic floor anatomic structures were evaluated and segmented by MRI. Of 29 athletes (11 asymptomatic, 18 symptomatic), demographics, sport characteristics, and pelvic exam findings were not statistically different between groups. Symptomatic athletes had significantly worse urinary symptoms (median LURN SI-29 8.5 vs. 8.0, P=0.022) and genitourinary pain (median GUPI 7 vs. 3, P=0.036), greater anterior thickness of the striated urethral sphincter muscle (median 2.5 vs. 1.8 mm, P=0.016) and puborectalis and levator ani muscles (median 10.3 vs. 8.6 mm, P=0.028), and worse disordered eating (median BEDA-Q 7.5 vs. 4.5, P=0.022). In nulliparous female elite athletes with UI, dynamic pelvic MRI identified differences in pelvic floor anatomy, which may be part of a multifactorial etiology of UI.