Three-dimensional ultrasound of pelvic floor: is there a correlation with delivery mode and persisting pelvic floor disorders 18-24 months after first delivery?

OBJECTIVE: Three-dimensional (3D) transperineal ultrasound has been shown to be a reliable and reproducible method for visualization of morphological changes in the female levator ani muscle. The aim of this study was to evaluate the relationship between persisting pelvic floor disorders 18-24 months after first delivery, biometric measurements of the pelvic floor and mode of delivery.
METHODS: In this prospective observational study, we recruited on their second day after delivery 130 primiparous women. All were Caucasian and their pregnancies had been singleton with cephalic presentation. 3D transperineal ultrasound was performed, with standardized settings, on the second day (results published previously) and 18-24 months after delivery. Volumes were obtained at rest and on Valsalva maneuver and biometric measurements of the levator hiatus were determined in the axial plane. Obstetric and constitutional parameters were obtained from our clinical files and, 18-24 months after the delivery, a standardized questionnaire was used to evaluate persisting pelvic floor disorders. Ultrasound measurements at 18-24 months were compared according to clinical symptoms of pelvic floor disorders and mode of delivery, including a subgroup analysis of vaginal (spontaneous vs operative vaginal) and Cesarean (primary i.e. elective vs secondary i.e. after onset of labor) delivery groups.
RESULTS: Seventy-seven (59%) women had complete follow-up at 18-24 months. Biometric measurements showed a significantly larger hiatal area in the vaginal delivery group than in the Cesarean section group 2 years after delivery (P < 0.01), whereas subgroup analysis within the vaginal and Cesarean delivery groups did not show significant differences. Although there was no statistical correlation between delivery mode and persisting stress urinary incontinence, women with persisting stress urinary incontinence 2 years after delivery had a larger hiatal area than did women without this clinical symptom (P < 0.01). There were no significant differences in hiatal dimensions in women with bladder urgency or dyspareunia.
CONCLUSIONS: 3D transperineal ultrasound, which is easily accessible, can provide useful information on morphological changes of the female pelvic floor. Women with a spontaneous or operative vaginal first delivery had a significantly larger hiatal area and axial distension than did women whose first delivery was by Cesarean section, even 2 years after delivery. Performing 3D ultrasound after the first delivery may help to identify women at high risk for persisting pelvic floor disorders.