A Grading System for Urinary Dysfunction Enabling Risk-Stratified Management After Vaginal Delivery Based on a Prospective Observational Study

Background: Urinary dysfunction is a common complication following vaginal delivery, yet the lack of a standardized assessment system results in delayed diagnosis and suboptimal treatment. This study aims to develop a novel urinary function grading system to evaluate the urogynecological impact of childbirth, identify associated risk factors, and guide the development of evidence-based, targeted nursing interventions. Methods: In this prospective observational study, 370 primiparous women who experienced spontaneous vaginal delivery at Nanfang Hospital between 1 January 2020 and 1 January 2021 underwent systematic urological evaluations during hospitalization and at a 6-week follow-up. Urinary function was graded (Ⅰ–Ⅳ) based on post-void residual (PVR) volume and clinical symptoms: Grade I, normal function (PVR <50 mL without voiding dysfunction); Grade II, mild dysfunction (urinary frequency with PVR <50 mL); Grade III, moderate dysfunction (PVR >50 mL); and Grade IV, severe dysfunction (urinary retention requiring catheterization or stress urinary incontinence [SUI]). Urodynamic parameters, including urinary interval, urine volume, initiation time, and voiding duration, were collected for statistical analysis. Results: Progressive deterioration of urinary parameters was significantly associated with increasing severity grades (I–III) (all p < 0.001). On postpartum day 1, 74.054% of women exhibited urinary dysfunction, which declined markedly over time. By day 14 postpartum, 10.270% of women developed SUI, with a higher proportion initially classified as Grade I (84.211%). The age, neonatal weight, total duration of labor, operative vaginal delivery, episiotomy, and labor analgesia were significantly associated with urinary function grading (all p < 0.05). Among these, prolonged labor, labor analgesia, and operative vaginal delivery emerged as independent risk factors for Grade IV urinary dysfunction (all p < 0.05). Conclusions: The grading system enables risk-stratified management of postpartum urinary function, promoting early identification and timely intervention for urinary dysfunction. Clinically, emphasis should be placed on managing high-risk factors and providing targeted nursing care to mitigate the impact of vaginal delivery on maternal urinary function. Further studies are needed to validate and refine this grading system.