Levator Ani Deficiency and Pelvic Organ Prolapse Severity

OBJECTIVE: To estimate whether levator ani deficiency severity is a predictor of clinically significant pelvic organ prolapse (POP) and to determine whether there is a levator ani deficiency threshold above which POP occurs. METHODS: Two-hundred twenty three-dimensional ultrasound scans performed on urogynecologic clinic patients were reviewed, and each levator ani muscle subdivision was individually scored (0=no defect, 1=50% or less defect, 2=more than 50% defect, 3=total absence of the muscle) on each side. A levator ani deficiency score was calculated and categorized as mild (score 0-6), moderate (score 7-12), and severe (score more than 13). Clinically significant prolapse was defined as stage 2 or higher. RESULTS: The mean age was 56.50 (standard deviation +/- 15.58) and median parity was 2 (range 0-6). A mild positive correlation was demonstrated between levator ani deficiency category and prolapse stage (r(s)=0.44; P<.001). Score distribution significantly differed by prolapse stage (P<.001). No patients with stage 3 prolapse had a levator ani score less than 6, and no patients with stage 4 prolapse had a levator ani score less than 9. In patients with prolapse, those with moderate levator ani deficiency had 3.2 times the odds of POP compared with patients with a minimal defect; those with severe levator ani deficiency had 6.4 times the odds of prolapse than those with minimal deficiency. CONCLUSIONS: Levator ani deficiency severity is associated with clinically significant prolapse.