title: Delivery mode is a major environmental determinant of stress urinary incontinence: results of the Evanston-Northwestern Twin Sisters Study.
abstract: OBJECTIVE
  We studied a large cohort of identical twin sisters, utilizing the unique properties of a twin research design to explore the relationship between obstetrical delivery mode and stress urinary incontinence.
  
  
  METHODS
  An anonymous 67-item survey was completed by 271 identical twin pairs (n = 542) at the world's largest annual gathering of twins. Logistic regression for repeated binary measures was used to evaluate risk factors and accounting for shared genetics within pairs.
  
  
  RESULTS
  The twins had a mean age of 47.1 years (range 15 to 85 years), and stress urinary incontinence was reported by 51.8%. Stress urinary incontinence was associated with age (P = .001), parity (P = .001), obesity (P = .002), and birth mode, with vaginal delivery conferring a considerable increase in stress urinary incontinence risk relative to cesarean section (odds ratio 2.28, 95% confidence interval 1.14 to 4.55, P = .019).
  
  
  CONCLUSIONS
  Vaginal delivery mode represents a potent determinant of stress urinary incontinence, carrying more than twice the risk of cesarean section. This study of identical twins provides new insight into the epidemiology of female incontinence.
authors.affiliation: Evanston Continence Center, Northwestern University Medical School, Evanston, IL 60201, USA. rgoldberg@enh.org
authors.forename: Roger P
authors.initials: RP
authors.lastname: Goldberg
authors.forename: Yoram
authors.initials: Y
authors.lastname: Abramov
authors.forename: Sylvia
authors.initials: S
authors.lastname: Botros
authors.forename: Jay-James
authors.initials: JJ
authors.lastname: Miller
authors.forename: Sanjay
authors.initials: S
authors.lastname: Gandhi
authors.forename: Angel
authors.initials: A
authors.lastname: Nickolov
authors.forename: Wendy
authors.initials: W
authors.lastname: Sherman
authors.forename: Peter K
authors.initials: PK
authors.lastname: Sand
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002585:Cesarean Section; D036861:Delivery, Obstetric / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D014550:Urinary Incontinence, Stress / Q000209:etiology*