Is bladder neck and urethral mobility associated with urinary incontinence and mode of delivery 4 years after childbirth?

Abstract

Aims: To study changes in bladder neck, urethral mobility and urinary incontinence (UI) from pregnancy to 4 years postpartum and demonstrate any association to mode of delivery or presence of levator ani muscle (LAM) injury. Secondly, we aimed to correlate bladder neck and urethral mobility to UI symptoms.

Methods: Prospective study of 180 women, recruited in their first pregnancy and followed up 1 and/or 4 years postpartum. UI symptoms were assessed with a validated questionnaire. All underwent 4D transperineal ultrasound to assess LAM injury, bladder neck descent (BND), retrovesical angle at Valsalva (RVA), and urethral rotation between rest and Valsalva. A mixed model compared changes over time, different delivery modes, and women with and without LAM injury. Spearman's rank correlation tested the correlation of BND, RVA, and urethral rotation to UI symptoms.

Results: BND, RVA, and urethral rotation all increased following delivery. From 1 to 4 years postpartum, a larger increase in BND was found for women delivered vaginally with LAM injury, compared to women with intact LAM (P = 0.02) and women with cesarean section (P = 0.046). One year postpartum, BND and RVA correlated to UI symptoms, r_s = 0.22, P = 0.01. Four years postpartum, RVA correlated to UI symptoms, r_s = 0.19, P = 0.02.

Conclusions: Although bladder neck and urethral mobility increased from pregnancy to 4 years postpartum irrespective of delivery mode, women with LAM injury had larger increase in BND, suggesting that this is important in the pathogenesis of bladder neck mobility and could lead to pelvic floor dysfunction in the long term.

Keywords: 3D/4D ultrasound; bladder neck descent; cesarean section; levator ani muscle injury; pelvic floor disorders; urethra/physiopathology; vaginal delivery.