Objective To examine the effect of pregnancy pilates-assisted birth preparation training on urinary incontinence UI including during pregnancy, and the postpartum period and birth outcomes. Design The randomized controlled experimental study Setting Gynecology and Pregnancy Education Counseling Center Population Nulliparous pregnant women (n=126) at 28-30 weeks of gestation Method The was carried out between March and August 2022. Participants were divided into two groups by a simple random sampling method. Intervention was applied twice in a week, a total of eight weeks to pilates group. The control group was given routine obstetric and pregnancy care. A personal data form and the M-ISI were used as data collection tools. The data obtained were analyzed using the program SPSS 20. Main outcome measures A moderate-intensity prenatal pilates exercise program reduces the severity of UI symptoms during pregnancy and the early postpartum period. Results The mean weight gains of women who participated to the experimental group during pregnancy was significantly lower than the control group. While 80.6% of women who received pilates-assisted childbirth preparation training gave birth vaginally, this rate in the control group was 54.2%. The duration of labor mean score of pilates group was five hours and 43 minutes less than the duration of labor of the control group. After intervention, and postpartum period, the SUI severity of the experimental group was significantly lower than that of the control group. Conclusion Pilates-assisted childbirth preparation training reduced the severity of UI symptoms during pregnancy and the early postpartum. In addition, the decrease in weight gain during pregnancy and the increase in the vaginal birth rate contributed to the shortening of the duration of labor.