Ultrasonographic anatomy of perineal structures during pregnancy and immediately following obstetric injury.
OBJECTIVES: To assess perineal anatomy using ultrasound before and immediately after delivery. METHODS: Structures in the perineum were studied by real-time two-dimensional transvaginal and endoanal ultrasound imaging using a combined linear and semicircular (up to 200 degrees sector) probe. We examined 45 nulliparous pregnant women and 44 primiparae immediately after delivery (40 with anal sphinc
