This objective of this study was to examine changes in pelvic floor morphology in a cohort of primiparous women. Approximately 85% had vaginal and 15% had cesarean deliveries. Demographic characteristics of the patients lost to follow-up were similar to the patients not lost to follow-up. In the vaginal group, a significant reduction in all measurements was seen during the first 6 months postpartum, being most pronounced for the levator hiatus area during Valsalva maneuver (-3.5 cm; P<.001). In the cesarean delivery group, no significant changes between examination points were found postpartum. Only the vaginal delivery group exhibited significant increases in all measurements when comparing the status at 12 months postpartum with 21 weeks of gestation, most pronounced for levator hiatus area during Valsalva maneuver (3 cm; P<.001). However, comparing the two delivery groups at 12 months postpartum, the only significant difference found was levator hiatus area during contraction.
This study concluded that the levator ani muscle has the ability to recover after pregnancy and delivery, although not all women recover to pregnancy level. The majority of recovery takes place during the first 6 months postpartum. Significant pregnancy-induced changes are not shown to persist 1 year postpartum.