Ultrasound imaging of the female perineum: the effect of vaginal delivery on pelvic floor dynamics.

OBJECTIVE

To assess the use of perineal ultrasound in the evaluation of the influence of vaginal delivery on urethral mobility and on the contraction strength of the levator ani muscles.

METHODS

This was a prospective observational study of 70 nulliparous women. Each woman underwent perineal ultrasound assessment at 36-38 weeks' gestation and at 1 week and 3 months following delivery. During each examination we assessed: the posterior urethrovesical angle at rest, urethral mobility during Valsalva maneuver and movement of the anorectal angle and levator sling angle during contraction of the levator ani.

RESULTS

The urethrovesical angle and the urethral mobility increased significantly after delivery (P < 0.0001). The levator sling excursion decreased proportionally. The anorectal excursion had decreased significantly by the examination 3 months after birth.

CONCLUSIONS

Perineal sonography provides objective assessment criteria for urethral mobility and for contraction strength of the levator ani muscles and detects changes in the anatomy and function of the pelvic floor after vaginal delivery.