Introduction and Hypothesis <p>Studies concerning the similarities and differences in relevant factors for PPUI in&#xa0;puerpera with delivery modes are scarce. This study aimed to investigate relevant factors for PPUI among primiparas grouped by different delivery modes using transperineal ultrasonography.</p> Methods <p>This is a&#xa0;retrospective cohort&#xa0;study. Seven hundred thirty-eight primiparas were included and their clinical and ultrasonographic data were collected. First, they were divided into the UI group (<i>n</i> = 233) and non-UI group (<i>n</i> = 505). Then all participants were redivided into the vaginal delivery without episiotomy group (<i>n</i> = 271), the vaginal delivery with episiotomy group (<i>n</i> = 158), and the cesarean section group (<i>n</i> = 309). Independent relevant factors of PPUI were analyzed with the delivery mode as one of the variables and as a grouping factor, respectively.</p> Results <p>BMI, delivery modes, vertical distances between the location of bladder neck and the reference line of the inferior symphyseal margin at rest (BSDr), and [bladder neck descent (BND)]/BSDr were independently associated with PPUI in the overall study population. Among the participants grouped by delivery modes, the maternal BMI, BSDr, and retrovesical angle during Valsalva maneuver (RVAv) were independently associated with PPUI in the vaginal delivery without episiotomy group. BND/BSDr was the independent relevant factor of PPUI in the cesarean section group. In the vaginal delivery with episiotomy group, no factors were independently associated with PPUI.</p> Conclusions <p>The independent relevant factors for PPUI in primiparas varied with delivery modes. Sonographic measurements were independently associated with PPUI related to different delivery modes, acting as differential markers to identify PPUI.</p>