Pelvic Floor Disorders after Obstetric Avulsion of the Levator Ani Muscle

With vaginal childbirth, 10% to 30% of women sustain levator ani muscle avulsion. The objective of this study was to estimate the cumulative incidence of prolapse and other pelvic floor disorders (PFDs), comparing vaginally parous women with and without levator avulsion. Methods Parous women enrolled in a longitudinal study were assessed annually for PFDs with the Pelvic Organ Prolapse Quantification Examination (for prolapse) and the Epidemiology of Prolapse and Incontinence Questionnaire (for stress incontinence, overactive bladder, and anal incontinence). Three-dimensional transperineal ultrasound was used to identify levator avulsion. Women with and without levator avulsion after vaginal delivery were compared for the cumulative incidence of PFDs. Further analysis also stratified by forceps delivery. Results At the time of assessment, 453 participants were 6 to 17 years from first delivery (median, 11 years). Levator avulsion was identified in 15% (66/453) and was more common among those who had undergone forceps-assisted delivery (P < 0.001). Levator avulsion was strongly associated with prolapse beyond the hymen (odds ratio, 2.7; 95% confidence interval, 1.3-5.7) and with symptoms of prolapse (odds ratio, 3.0; 95% confidence interval-1.2, 7.3). These associations persisted after controlling for forceps-assisted delivery. In contrast, the odds of stress incontinence, overactive bladder, and anal incontinence were marginally (but not significantly) increased among women with levator avulsion in this cohort. Conclusions Obstetric levator avulsion is strongly associated with pelvic organ prolapse. The relationship between levator avulsion and other PFDs may not be significant.