This study aimed to evaluate the prevalence of urinary incontinence (UI) and its associated risk factors among pregnant Korean women, as UI significantly impacts their quality of life. A cross-sectional study involving singleton pregnant women was conducted between April and December 2023. Data were collected using a questionnaire assessing demographic information and UI symptoms. The International Consultation on Incontinence Questionnaire-UI short form was used to diagnose UI. A total of 824 pregnant women from three centers participated, with an overall prenatal UI prevalence of 40.2% (331/824). Stress UI was most common (77.1%), followed by mixed UI (16.9%), and urgency UI (6.0%). Risk factors for UI included prior delivery mode, specifically vaginal delivery (adjusted odds ratio [aOR], 5.61; 95% confidence interval [CI], 1.40-22.50; P=0.015) and combined vaginal and cesarean delivery (aOR, 23.14; 95% CI, 1.77-302.74; P=0.017). Additionally, second trimester (aOR, 1.99; 95% CI, 1.19-3.32; P=0.009) and third trimester (aOR, 4.44; 95% CI, 2.65-7.40; P<0.001) were associated with increased UI risk. Conversely, drinking alcohol before pregnancy was a protective factor (aOR, 0.72; 95% CI, 0.53-0.99; P=0.046). Approximately 40% of Korean pregnant women experience prenatal UI. Prior delivery mode and advanced gastrointestinal age are significant risk factors. Further research with postpartum and long-term follow-ups is needed.