title: Parturition events and risk of urinary incontinence in later life.
abstract: OBJECTIVE
  To examine the association between specific events during vaginal deliveries and urinary incontinence later in life.
  
  
  METHODS
  A retrospective cohort study of 1,521 middle-aged and older women with at least one vaginal delivery who were long-term members of an integrated health delivery system. Age, race/ethnicity, current incontinence status, medical, surgical history, pregnancy and parturition history, menopausal status, hormone replacement, health habits, and general health were obtained by questionnaire. Labor and delivery records, archived since 1948, were abstracted by professional medical record abstractors to obtain parturition events including induction, length of labor stages, type of anesthesia, episiotomy, instrumental delivery, and birth weight. The primary dependent variable was current weekly urinary incontinence (once per week or more often) versus urinary incontinence less than monthly (including no incontinence) in past 12 months. Associations of parturition events and later incontinence were assessed in multivariate analysis with logistic regression.
  
  
  RESULTS
  The mean age of participants was 56 years. After adjustment for multiple risk factors, weekly urinary incontinence significantly associated with age at first birth (P = 0.036), greatest birth weight (P = 0.005), and ever having been induced for labor (OR = 1.51; 95%CI = 1.06-2.16, P = 0.02). Risk of incontinence increased from OR = 1.35 (95%CI = 0.92-1.97, P = 0.12) for women with one induction to OR = 2.67 (95%CI = 1.25-5.71, P = 0.01) for women with two or more inductions (P = 0.01 for trend). No other parturition factors were associated with incontinence.
  
  
  CONCLUSIONS
  Younger age at first birth, greatest birth weight, and induction of labor were associated with an increased risk of incontinence in later life.
authors.affiliation: Department of Family and Community Medicine, University of California, San Francisco, San Francisco, California, USA. dthom@fcm.ucsf.edu
authors.forename: David H
authors.initials: DH
authors.lastname: Thom
authors.forename: Jeanette S
authors.initials: JS
authors.lastname: Brown
authors.forename: Michael
authors.initials: M
authors.lastname: Schembri
authors.forename: Arona I
authors.initials: AI
authors.lastname: Ragins
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Creasman
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Van Den Eeden
mesh_terms: D000328:Adult; D000367:Age Factors; D001724:Birth Weight; D005260:Female; D006801:Humans; D007751:Labor, Induced / Q000009:adverse effects; D007743:Labor, Obstetric; D016015:Logistic Models; D008390:Markov Chains; D008875:Middle Aged; D009010:Monte Carlo Method; D016017:Odds Ratio; D036801:Parturition; D011247:Pregnancy; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014549:Urinary Incontinence / Q000209:etiology*