Pelvic floor muscle strength predicts stress urinary incontinence in primiparous women after vaginal delivery.

Introduction And Hypothesis: This study aimed to investigate obstetrical, neonatal, and clinical predictors of stress urinary incontinence (SUI) focusing on pelvic floor muscle (PFM) strength after vaginal delivery.

Methods: A cross-sectional study was used, and potential predictors of SUI were collected 5-7 months postpartum on 192 primiparous women. Predictors that reached significance in the bivariate analysis were entered into the Classification and Regression Tree that identified interactions among them and cutoff points to orient clinical practice.

Results: PFM strength was the strongest predictor of SUI. A combination of PFM strength ≤ 35.5 cmH(2)O, prior SUI, newborn weight > 2.988 g, and new onset of SUI in pregnancy predicted SUI. The model's accuracy was high (84%; p = 0.00).

Conclusions: From the four predictors identified, three are modifiable by physical therapy. This could be offered to women targeting at PFM strength >35.5 cmH(2)O at the postpartum as well as at the prevention of SUI before and during pregnancy.