Three-dimensional ultrasound of the female pelvic floor and 3D-power doppler angiography to assess endopelvic vascularization in pregnancy and puerperium

Abstract

Introduction and hypothesis: We studied ten different three-dimensional ultrasound (3D-US) and three-dimensional Power-Doppler angiography (3D-PDA) variables to assess female pelvic floor status and endopelvic vascularization. We hypothesize that 3D-US is a reliable method to determine and evaluate changes occurring in the pelvic floor during normal pregnancy and puerperium, and can be used by any urogynecology specialist with US-imaging experience. We aimed to validate this method for clinical application.

Materials and methods: We performed a prospective study of 162 nulliparous pregnant women evaluated at weeks 12, 28 and 36, and at 48 hours postpartum and three months post-delivery. At each of the five visits, we performed transperineal 3D-US of the pelvic floor and 3D-PDA to assess periurethral vascularization.

Results: Quantification of the vaginal anterior vaginal wall anchors (AWA) is an anthropometric parameter sensitive to changes in pregnancy and puerperium. Significant differences in AWA were observed according to delivery mode, being lower in vaginal deliveries than cesarean sections and even lower in prolonged labor deliveries and those in which episiotomy was performed. Posterior uretrovesical angle (UVA) increased during pregnancy, partially recovering after delivery although less so in those with epidural analgesia. Urethral sphincter volume (USV) decreased significantly during labor and postpartum. Periurethral vascularization increased during pregnancy and decreased significantly after delivery. Levator hiatus area (LHA) increased during pregnancy and decreased after delivery. Patients who received epidural analgesia and oxytocin showed better LHA recovery. Prolonged labor and greater fetal head circumference increased LHA. The anorectal angle (ARA) increased during pregnancy and decreased postpartum.

Conclusion: All 3D-US variables and their changes during pregnancy, childbirth and the postpartum period are measurable using the Virtual Computer-Aided Analysis (VOCAL method) with automatic threshold, which is more reliable and faster for measuring USV. AWA as an important new biometric parameter should be included in the study of the pelvic floor.