Impact of hysterectomy on stress urinary incontinence: an identical twin study

Objective: This study uses the unique properties of twin research design to evaluate whether hysterectomy impacts stress urinary incontinence (SUI). Study Design: As part of the Evanston Twins Sister Study, we performed bivariate and multivariate analyses on 83 identical twin pairs discordant for hysterectomy. Results: In bivariate analysis, SUI was less common in women who had prior hysterectomy (P =0.028). Multivariate analysis suggested that SUI was significantly less common after hysterectomy (odds ratio [OR], 0.55, confidence interval [CI], 0.30 to 1.00). Exclusion of twin pairs with a history of pelvic floor defect surgery eliminated the statistical relationship between hysterectomy and SUI (OR, 0.79, CI, 0.4 to 1.40). Conclusion: Hysterectomy, when analyzed with all cases, was associated with reduced SUI. When concurrent pelvic floor defect surgeries were excluded from the analysis, we found no relationship between hysterectomy and the risk of SUI afterward.