Pelvic structure and function at 1 month compared to 7 months by dynamic magnetic resonance after vaginal birth.

OBJECTIVE: We sought to determine whether changes exist in location and movement of pelvic floor structures at 1 and 7 months postpartum. STUDY DESIGN: Midsagittal magnetic resonance images from 13 primiparous women with birth events associated with levator ani damage at early (similar to 1 month) and late (similar to 7 months) postpartum time points were analyzed. Pelvic floor structure locations at rest and displacements from rest to maximum Kegel and Valsalva were determined. Urogenital and levator hiatus diameters were measured as well. RESULTS: The perineal body was 7.1 mm and anal verge 7.9 mm higher at 7 months postpartum (P = .003). Both the urogenital and levator hiatus diameters were smaller at 7 months (P < .05). Displacement during Kegel and Valsalva was similar between the 2 time points. CONCLUSION: Resting locations of the perineal body and anal verge are higher at 7 months postpartum, but the amount of movement during Kegel or Valsalva does not change.