Background: Adult women of all ages are frequently affected by urinary incontinence (UI), which can have a detrimental effect on quality of life. Although the cause of UI is complex, several major risk factors include aging, obesity, and unfavorable obstetric events.  The genesis of UI has been linked to pregnancy and childbirth. The impact of childbirth on the risk of UI is still up for debate, despite numerous research showing a clear, short-, medium-, and long-term correlation between UI and vaginal delivery. 
Objective: To study the  prevalence and  risk  factors  of  urinary incontinence   in nulliparous women  in  Mansoura  university  hospitals  , the  prevalence   of  postpartum  urinary  incontinence and  the  effect of  mode of  delivery on  the   prevalence  postpartum  urinary  incontinence.
Patients and Methods: The present study was a cross sectional study at Mansoura university hospitals (MUH) including nulliparous pregnant women. 105 Pregnant women asked to answer a questionnaire. urine leakage that occurs involuntarily during effort, exertion, sneezing, or coughing is known as SUI leakage; urine leakage that occurs involuntarily during effort, exertion, or right before urgency is known as UUI leakage; and urine leakage that occurs involuntarily during exertion, effort, sneezing, or coughing is known as MUI leakage.
Results: The study  also questioned change in urination style, complaints related to the urinary system frequency of urination during follow up and illustrates that there is statistically significant increase in frequency of urination from 5.7% ranging from 11-15 times/day that increased to 11.4% ranging from 11 to 15 times/ day in second trimester then become 31.4% from 11 to 15 times/ day then decrease of frequency of urination to 5.7% from 11 to 15 , 1% more than 15 times/day that decreased to 7.6% from 5 to 10 and 92.4% from 0 to 5 at 3 months. .A statistically significant increase in frequency of nocturnal urination during follow up from first to second trimester then 3rd trimester then decrease for 48 hours , one  month and 2 months follow up. For first trimester; 51.4% none , 22.9% twice , 17.1% once and 8.6% three times. .A statistically significant increase incidence of  burning during micturition during follow up from first to second trimester then 3rd trimester then decrease for 48 hours , one  month and 2 months follow up. significant change in amount of urine during follow up from first trimester to one month (p<0.001) and from first trimester to 3 months follow up (p=0.002).
Conclusion: Urinary incontinence is one of the common disorders during pregnancy and postpartum period which can affect quality of women's life significantly. The effect of mode of delivery C.S 77.1% and vaginal delivery 22.9%. a non-statistically significant relation between urinary  incontinence during follow up and age , period of gestation and mode of delivery among studied cases (p>0.05).