OBJECTIVE: To investigate the association of bladder neck position, bladder neck mobility, and levator hiatal dimensions with symptoms of stress urinary incontinence (SUI) using transperineal ultrasonography in women during and after their first pregnancy.
METHODS: In this prospective observational study, 280 nulliparous pregnant women were evaluated at 12 weeks of gestation, 36 weeks of gestation, and 6 months postpartum. At each visit, symptoms of SUI were assessed and transperineal ultrasound examination was performed at rest, on pelvic floor contraction, and on Valsalva maneuver. Bladder neck position, bladder neck mobility, and levator hiatal dimensions were determined offline. Independent-samples t tests were used to compare ultrasound data between women with and without SUI. Because multiple t tests were performed, the statistical significance level was corrected using the Bonferroni method.
RESULTS: There were 18.8% women who reported symptoms of SUI at 12 weeks of gestation, 47.2% at 36 weeks of gestation, and 37.5% at 6 months postpartum. During pregnancy, women with SUI had a significantly larger hiatal area compared with women without SUI (P=.001–.003). After childbirth, women with SUI had a significantly more caudal and dorsal position of the bladder neck on Valsalva maneuver than women without SUI (P=.004 and P=.001, respectively). There were no significant differences in bladder neck mobility between women with and without SUI.
CONCLUSION: Stress urinary incontinence during first pregnancy is associated with a larger hiatal area. After childbirth, SUI is associated with a more caudal and dorsal position of the bladder neck on Valsalva maneuver.