title: The prevalence of urinary incontinence 20 years after childbirth: a national cohort study in singleton primiparae after vaginal or caesarean delivery.
abstract: OBJECTIVE
  To investigate the prevalence and risk factors for urinary incontinence (UI) 20 years after one vaginal delivery or one caesarean section.
  
  
  METHODS
  Registry-based national cohort study.
  
  
  METHODS
  Women who returned postal questionnaires (response rate 65.2%) in 2008.
  
  
  METHODS
  Singleton primiparae who delivered in the period 1985-1988 with no further births (n = 5236).
  
  
  METHODS
  The Swedish Pregnancy, Obesity and Pelvic Floor (SWEPOP) study linked Medical Birth Register (MBR) data to a questionnaire about UI.
  
  
  METHODS
  Prevalence of UI and UI for more than 10 years (UI > 10 years) were assessed 20 years after childbirth.
  
  
  RESULTS
  The prevalence of UI (40.3 versus 28.8%; OR 1.67; 95% CI 1.45-1.92) and UI > 10 years (10.1 versus 3.9%; OR 2.75; 95% CI 2.02-3.75) was higher in women after vaginal delivery than after caesarean section. There was no difference in the prevalence of UI or UI > 10 years after an acute caesarean section or an elective caesarean section. We found an 8% increased risk of UI per current body mass index (BMI) unit, and age at delivery increased the UI risk by 3% annually.
  
  
  CONCLUSIONS
  Two decades after one birth, vaginal delivery was associated with a 67% increased risk of UI, and UI > 10 years increased by 275% compared with caesarean section. Our data indicate that it is necessary to perform eight or nine caesarean sections to avoid one case of UI. Weight control is an important prophylactic measure to reduce UI. Current BMI was the most important BMI-determinant for UI, which is important, as BMI is modifiable.
authors.affiliation: Department of Obstetrics and Gynaecology, Sahlgrenska Academy at Gothenburg University, Gothenburg, SwedenDepartment of Obstetrics and Gynaecology, Södra Älvsborgs Hospital, Borås, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Gyhagen
authors.affiliation: Department of Obstetrics and Gynaecology, Sahlgrenska Academy at Gothenburg University, Gothenburg, SwedenDepartment of Obstetrics and Gynaecology, Södra Älvsborgs Hospital, Borås, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Bullarbo
authors.affiliation: Department of Obstetrics and Gynaecology, Sahlgrenska Academy at Gothenburg University, Gothenburg, SwedenDepartment of Obstetrics and Gynaecology, Södra Älvsborgs Hospital, Borås, Sweden.
authors.forename: T F
authors.initials: TF
authors.lastname: Nielsen
authors.affiliation: Department of Obstetrics and Gynaecology, Sahlgrenska Academy at Gothenburg University, Gothenburg, SwedenDepartment of Obstetrics and Gynaecology, Södra Älvsborgs Hospital, Borås, Sweden.
authors.forename: I
authors.initials: I
authors.lastname: Milsom
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002585:Cesarean Section; D015331:Cohort Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008423:Maternal Age; D008875:Middle Aged; D010298:Parity; D036801:Parturition; D011247:Pregnancy; D015995:Prevalence; D012042:Registries; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D014549:Urinary Incontinence / Q000453:epidemiology* / Q000209:etiology