ABSTRACTBackgroundUrinary incontinence (UI) is a frequent pathology that causes significant harm to the well-being and quality of life of pregnant women. This study aimed to measure the prevalence and to identify factors associated with the occurrence of UI during pregnancy in women living in the municipality of Rio Grande (RS), Southern Brazil, in 2016.MethodsThis is a cross-sectional population-based study that included all puerperae living in this municipality who had a child in one of the two local maternity hospitals between January 1 and December 31, 2016. The interviews were held at the hospital within 48 hours after delivery, when previously trained interviewers used a single, standardized questionnaire, seeking information on maternal demographic, behavioral and reproductive/obstetric history, as well as socioeconomic status of the household and care received during pregnancy and childbirth. The multivariate analysis followed a previously defined hierarchical model, using Poisson regression with robust variance adjustment and prevalence ratio (PR) as measure of effect.ResultsAmong the 2,716 puerperae identified, 2,694 (99.2%) participated in this study. The prevalence of urinary incontinence in the gestational period was 14.7% (95%CI: 13.4%-16.1%). The lowest observed UI rate (8.3%) occurred among adolescent mothers (<20 years), while the highest occurred among those who reported frequent urinary urgency (39.2%). The probability of occurrence of UI, even after adjustment, was significantly higher among those who were older than 30 years old at current pregnancy, whose first pregnancy was before the age of 20 or after 30, who reached the end of gestation weighing 90 kg or more, who exercised regularly during pregnancy and who reported frequent urinary urgency during the gestational period.ConclusionsUrinary incontinence showed a high prevalence in the study population. The identified risk factors can be well administered at primary health care level. The recommendation of regular physical exercise in pregnancy must be reviewed and better investigated with more robust designs because of possible facilitators for the occurrence of UI in this period.