Longitudinal comparison study of pelvic floor function between women with and without stress urinary incontinence after vaginal delivery.

Purpose: To compare the pelvic floor function between women with and without stress urinary incontinence after vaginal delivery.
Methods: Seventeen women (age 35.5 ± 3.5) were prospectively studied at about 6 weeks, 3 months, and 6 months after vaginal delivery. Urinary incontinence was assessed by the International Consultation on Incontinence Questionnaire - Short Form. Pelvic floor function was assessed by antero-posterior diameter of the levator hiatus using transperineal ultrasound.
Results: Five of 17 women experienced postpartum stress urinary incontinence. The antero-posterior diameter of the levator hiatus at rest was significantly longer in stress urinary incontinent women than in continent women until 3 months after delivery (p < 0.01), though shortening of the antero-posterior diameter of the levator hiatus was not significantly different between continent women and stress urinary incontinent women. Regardless of urinary incontinence, the antero-posterior diameter of the levator hiatus at rest shortened at 6 months postpartum, compared to 6 weeks postpartum (p < 0.001). The antero-posterior diameter of the levator hiatus during contraction had shortened only in continent women by 6 months postpartum (p = 0.02).
Conclusion: The extended pelvic floor may be a cause of stress urinary incontinence in the postpartum period. Therefore, treatment to improve the extended pelvic floor should be developed for the prevention of stress urinary incontinence.