A randomized, double-blinded, sham-controlled trial of postpartum extracorporeal magnetic innervation to restore pelvic muscle strength in primiparous patients.

OBJECTIVE: The purpose of this study was to determine the effects of extracorporeal magnetic innervation (ExMI) on pelvic muscle strength of primiparous patients. STUDY DESIGN: Primigravid patients were randomized to receive either active or sham ExMI postpartum treatments for 8 weeks. The main outcome measure was pelvic muscle strength measured by perineometry at baseline (midtrimester), 6 weeks (before treatments), 14 weeks, 6 months, and 12 months postpartum. Mixed randomized-repeated measures ANOVA was used to analyze the mean perineometry values between the 2 groups and across all 5 time periods. RESULTS: Fifty-one patients enrolled, and 18 were lost to attrition. There were no differences in demographics or delivery characteristics between the active and sham groups. There was an overall time effect, F(3,85) = 3.1, P = .049, but no group, F(1,31) = 0.007, P = .94, or (group)(time) interaction, F(3,85) = 1.8, P = .15. CONCLUSION: We found no differences in pelvic muscle strength between patients receiving active or sham ExMI treatments in the early postpartum period.