Dynamic characteristics of the circumvaginal muscles during pregnancy and the postpartum.

Weakened circumvaginal muscles (CVM) may occur after childbirth and may be associated with obstetric factors such as perineal outcome, episiotomy, length of second stage labor, baby weight, and pushing technique. Pressures developed by the CVM during pregnancy and postpartum were obtained to test the hypothesis that significantly lower pressures would be developed by the CVM in the early postpartum than during pregnancy. The sample consisted of 29 pregnant women who planned to deliver at a birth center. A follow-up study was performed approximately one year after delivery to determine if improvement of the CVM occurred over time. The results supported the hypothesis and indicated that restitution of the CVM occurred after the early postpartum period.