Follow-Up Evaluation of the Effect of Vaginal Delivery on the Pelvic Floor.

PURPOSE: The aim of this study was to evaluate the effect of vaginal delivery on the pelvic floor by serial measurement of pudendal nerve terminal motor latency, perineal descent, and anal pressure before and after delivery. METHODS: Eighty pregnant females (40 primigravidae, 40 multigravidae) expecting vaginal delivery were prospectively evaluated. Measurements of pudendal nerve terminal motor latency, perineometry, and manometry were performed two to three months before delivery and two to three days, two months, and six months after delivery. RESULTS: Before delivery, pudendal nerve terminal motor latency showed no significant difference between primigravidae and multigravidae. Perineal plane at straining was lower and the descent was larger in multigravidae than primigravidae. Anal squeeze pressure was also lower in multigravidae than primigravidae. Two to three days after delivery, regardless of the group, pudendal nerve terminal motor latency was prolonged, perineal plane at straining became lower, the descent increased, and anal squeeze pressure decreased. Two months after delivery, pudendal nerve terminal motor latency recovered to the level before delivery. Perineal descent also recovered somewhat, but remained increased after six months had passed. In primiparae, perineal plane at straining remained lower after six months had passed. However, in multiparae the plane remained lower only for two months and recovered by six months postpartum. Anal squeeze pressure also showed a moderate recovery, but still remained significantly lower at six months postpartum. CONCLUSIONS: Pudendal nerve damage and functional impairment in the pelvic floor sphincter musculature occurs during vaginal delivery. Pudendal nerve terminal motor latency recovers after two months, whereas functional disturbance in the pelvic floor persists at least until six months. [ABSTRACT FROM AUTHOR]