Background Traumatic damage to fascial and muscular support structures during childbirth may be a major factor of the development of stress urinary incontinence (SUI) and pelvic organ prolapse (POP).The aim of this study was to prospectively investigate the role of different childbirth strategies on POP and SUI.Methods A total of 120 selected pregnant women were recruited and divided into two groups:vaginal delivery group (n=72)and selective cesarean delivery group(n=48).The women were questioned with SUI sheet and estimated with POP quantification (POP-Q) within 6-8 weeks after delivery.The correlations of SUI and results of POP-Q with the strategies of delivery were analyzed.ttest,X2 test,and the Mann-Witney test were used for statistical analysis.Results Among the 120 women,SUI was developed during 29-30 gestational weeks in 20 patients (16.6%),of whom 14 (70%) had symptoms of SUI till 6 weeks postpartum. Totally 20 (16.6%) women had SUI symptoms after delivery.The prevalence of postpartum SUI was positively correlated with the occurrence of SUI during 29-30 gestational weeks (P＜0.001).In the vaginal delivery group,100% of the women suffered form urinary prolapse 6 weeks postpartum,while 87.5% of those in the selective cesarean delivery group developed POP (P＜0.01). The percentages of the first-and second-degree urinary prolapse in the vaginal delivery group were 20.8% and 79.2% respectively,which were significantly different from those in the selective cesarean delivery group (64.6% and 22.9%;both P=0.000).Conclusions Pregnancy and delivery play an etiologic role in the development of SUI and POP. The onset of SUI during late pregnancy implies a significant risk of postpartum SUI symptoms.The prevalence of POP is significantly higher after vaginal delivery than after cesarean delivery.