Analysis of Pelvic Floor Structure Changes in Patients with Stress Urinary Incontinence After Vaginal Delivery Based on MRI Features

LI Jianbin; ZHAO Yaoyao; NIE Hongyan; LI Gang; FENG Yanxia; ZHANG Yuan; WANG Lishun

doi:10.13730/j.issn.2097-2148.2025.12.008

Abstract：Objective To explore the changes of pelvic floor structure in patients with stress urinary incontinence(SUI)after vaginal delivery through magnetic resonance imaging(MRI).Methods A total of 90 primiparas who gave birth through vagina in author's hospital were selected as the research objects from July 2022 to July 2023,and they were divided into SUI group(n=47)and non-SUI group(n=43)according to whether there was SUI after 6 weeks of delivery.All subjects underwent pelvic dynamic and static MRI examination,univariate analysis was used to examine the differences in general data,morphological and functional indicators of the levator ani and sphincter of urethra between the two groups,multivariate Logistic regression analysis was used to analyze the influencing factors of SUI after vaginal deliv-ery,receiver operating characteristic(ROC)curves were plotted to evaluate the predictive efficacy of these influencing factors,and a nomogram was used to construct the predictive model.Results Compared with the non-SUI group,the SUI group had larger levator ani hiatus area(LHA),shorter uterine cervixto pubic coccyx line(U-PCL)and bladder neck to pubic coccyx line(B-PCL),longer bladder neck descent(BND),larger retro vesicourethral angle(RVA)and anterior angle of the urethra(AUA),higher propor-tion of bladder funnels and shorter static and dynamic functional urethral length(FUL),all these differences were statistically significant(all P＜0.05).Multivariate Logistic regression analysis showed that dynamic FUL(OR=0.697,P=0.001),dynamic RVA(OR=0.962,P=0.026)and bladder funnel(OR=9.585,P=0.003)were independent influencing factors for SUI after vaginal delivery.Results of the ROC curve indicated that the area under the curve(AUC)of the combined prediction of SUI after vaginal delivery by dynamic FUL,RVA and bladder funnel was 0.883[95％confidence interval(CI):0.798-0.941];the C-in-dex of the prediction model constructed based on dynamic FUL+bladder funnel+dynamic RVA for predicting SUI af-ter vaginal delivery was 0.883(95％CI:0.798-0.941).Conclusion The presence of bladder funnel,shortened FUL and increased RVA are influencing factors for early SUI after vaginal delivery,the combination of these three factors has good predictive efficacy for early SUI after vaginal delivery and can be used to predict the occurrence of early SUI after va-ginal delivery.