Levator ani denervation and reinnervation 6 months after childbirth.

Abstract

The objective of the study was to assess the prevalence of levator ani denervation and reinnervation 6 months after the first delivery. 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. 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. 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.