Multilevel musculo‐fascial defect magnetic resonance study of female pelvic floor: retrospective case control study in women with pelvic floor dysfunction after the first vaginal delivery

INTRODUCTION: Magnetic resonance imaging (MRI) provides a detailed display of the pelvic floor structures responsible for normal pelvic floor anatomy. The aim of the study is to assess the appearance of musculo‐fascial defects in women with pelvic floor dysfunction following first vaginal delivery. MATERIAL AND METHODS: Analysis of axial T3 (Tesla 3) MRI scans from a case control study of symptomatic (n = 149) and asymptomatic (n = 60) women after first vaginal delivery. Presence and severity of pelvic organ support and attachment system defects in three axial pelvic planes were assessed. RESULTS: In the symptomatic group, major muscular defects were found in 67.1% (for pubovisceral muscle complex) and 87.9% (for iliococcygeal muscle). Only 6.7% of major pubovisceral and 35.0% of major iliococcygeal defects were identified in the controls (p = 0.000). Prolapse patients had an odds ratio (OR) of 22.1 (95% CI 8.94–54.67) to have major pubovisceral muscle complex defect and OR of 4.9 (95% CI 1.51–15.71) to have major iliococcygeal muscle defect. Fascial defects were found in 60.4% and 83.2% the symptomatic group, respectively. Those with prolapse had an OR of 29.1 (95% CI 9.77–86.31) to have facial defect at the level of pubovisceral muscle complex and an OR of 16.9 (95% CI 7.62–37.69) to have fascial defect at the level of iliococcygeal muscle. Uterosacral ligaments detachment was associated with prolapse with an OR of 10.1 (95% CI 4.01–25.29). For the model based on combination on all MRI markers, the area under the receiver operating characteristic curve is 0.921. CONCLUSIONS: This study provides comprehensive data about first vaginal delivery‐induced changes in the levator ani muscle and endopelvic fascial attachment system. These changes are seen also in asymptomatic controls, but they are significantly less expressed.