Establishment and validation of a simple nomogram for predicting early postpartum stress urinary incontinence among women with vaginal delivery: a retrospective study.

Background: Stress urinary incontinence (SUI) is a common public health issue that negatively impacts the quality of life for women worldwide, of which early detection and rehabilitation are consequently pivotal. The aim of this study is to establish a simple nomogram for identifying women at risk of postpartum SUI.

Methods: A retrospective study was conducted in a tertiary specialized hospital in Shanghai, China. The study included only women with singleton, full-term, and vaginal deliveries. 2,441 women who delivered from July 2019 to November 2019 were included in the training cohort, and 610 women who delivered from January 2022 to February 2022 were included in the validation cohort. SUI was determined by the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI-SF). Univariate and multifactorial logistical regression were used to identify independent risk factors for postpartum SUI and further construct the nomogram accordingly. Based on concordance statistics (C-statistics), calibration curves, and decision curve analyses, we evaluated the performance of the nomogram in the training cohort and the validation cohort. In addition, the model was validated internally in the training cohort through cross-validation.

Results: There were no significant statistically differences in important baseline data such as age, pre-pregnancy BMI, and parity between the training and validation cohorts. SUI was observed in 431 (17.6%) and 125 (20.5%) women in the training and validation cohorts, respectively. According to the regression analysis, age, parity, second stage of labor, infant weight, and forceps delivery were included in the nomogram. The nomogram had a C-statistic of 0.80 (95% confidence interval [CI] 0.74-0.85) for predicting SUI. C-statistics were stable in both internally cross-validated training cohort (mean 0.81) and validation cohort (0.83 [95% CI 0.79-0.87]). The nomogram's calibration curve was near the ideal diagonal line. Additionally, the model exhibited a positive net benefit from the decision curve analysis.

Conclusion: We have created a nomogram that can be utilized to quantify the risk of postpartum SUI for women with vaginal delivery. The model might contribute to predicting early postpartum SUI, thereby facilitating the management of SUI.