OBJECTIVE: The objective of the study was to assess the prevalence of levator ani denervation and reinnervation 6 months after the first delivery. STUDY DESIGN: Ninety-six primigravida women underwent quantitative electromyography of the levator ani during the third trimester and twice postpartum. A 95% confidence interval for normal function was created using interference pattern analysis. Fifty-seven who completed the study are presented in this secondary data analysis. Postpartum muscle sites outside the normal range were considered abnormal. Obstetric and demographic characteristics were assessed. RESULTS: Of 57 subjects, 70% had no denervation. Of the 30% with denervation at 6 weeks, 35% recovered by 6 months. Obstetric or maternal characteristics were not predictive of denervation or reinnervation, except subjects with persistent denervation tended toward lower body mass index (BMI) independent of mode of delivery. CONCLUSION: Nearly one-third of women have levator ani denervation after first delivery, but many recover by 6 months. Denervation is not clearly associated with mode of delivery, but higher maternal BMI may be protective.