title: Urinary incontinence: prevalence and risk factors at 16 weeks of gestation.
abstract: OBJECTIVE
  To evaluate the prevalence of urinary incontinence at 16 weeks of gestation and to identify possible maternal and obstetric risk factors.
  
  
  METHODS
  Cross-sectional study and cohort study.
  
  
  METHODS
  Department of Obstetrics and Gynaecology, Aarhus University Hospital, Denmark.
  
  
  METHODS
  Cross-sectional study: 7795 women attending antenatal care. Cohort study: a sub-group of 1781 pregnant women with one previous delivery at our department.
  
  
  RESULTS
  Prevalence and maternal risk factors: the prevalence of urinary incontinence within the preceding year was 8.9% among women at 16 weeks of gestation (nulliparae, 3.9%, para 1, 13.8%, para 2+, 16.2%). Stress or mixed incontinence occurred at least weekly in 3% of all the women. After adjusting for age, parity, body mass index, smoking, previous abortions, and previous lower abdominal or urological surgery in a logistic regression model, primiparous women who had delivered vaginally had higher risk of stress or mixed urinary incontinence than nulliparous women (OR 5.7; 95% CI 3.9-8.3). Subsequent vaginal deliveries did not increase the risk significantly. Young age, body mass index > 30, and smoking were possible risk factors for developing urinary incontinence. Obstetric factors: weight of the newborn > 4000 g (OR 1.9; 95% CI 1.0-3.6) increased the risk of urinary incontinence; mediolateral episiotomy in combination with birthweight > 4000 g also increased the risk (OR 3.5; 95% CI 1.2-10.2); a number of other intrapartum factors did not increase the risk of urinary incontinence.
  
  
  CONCLUSIONS
  The first vaginal delivery was a major risk factor for developing urinary incontinence; subsequent vaginal deliveries did not increase the risk significantly. Birthweight > 4000 g increased the risk; episiotomy in combination with birthweight > 4000 g also increased the risk.
authors.affiliation: Department of Obstetrics and Gynaecology, Aarhus University Hospital, Denmark.
authors.forename: K E
authors.initials: KE
authors.lastname: Højberg
authors.forename: J D
authors.initials: JD
authors.lastname: Salvig
authors.forename: N A
authors.initials: NA
authors.lastname: Winsløw
authors.forename: G
authors.initials: G
authors.lastname: Lose
authors.forename: N J
authors.initials: NJ
authors.lastname: Secher
mesh_terms: D000293:Adolescent; D000328:Adult; D002585:Cesarean Section / Q000009:adverse effects; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D004841:Episiotomy / Q000009:adverse effects; D005260:Female; D006801:Humans; D009765:Obesity / Q000150:complications / Q000453:epidemiology; D007744:Obstetric Labor Complications / Q000453:epidemiology; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011262:Pregnancy Trimester, Second; D015995:Prevalence; D012307:Risk Factors; D014549:Urinary Incontinence / Q000453:epidemiology*