title: Use of oral contraceptives and uterine fibroids: results from a case-control study.
abstract: OBJECTIVE
  To analyse the association between oral contraceptive use and the risk of uterine fibroids.
  
  
  METHODS
  We considered data collected in a case-control study on risk factors for uterine fibroids.
  
  
  METHODS
  We studied 843 women with uterine fibroids, whose clinical diagnosis dated back no more than two years. Controls were 1557 non-hysterectomised patients younger than 55 years admitted for acute, non-gynecological, non-hormonal, non-neoplastic conditions.
  
  
  RESULTS
  A total of 254 cases (30.1%) and 360 controls (23.1%) reported ever using oral contraceptives: the odds ratio (OR) for ever vs never users was 1.1 (95% CI 0.8-1.3). The risk in current users was below unity when compared with never users (OR 0.3, 95% CI 0.2-0.6), while ex-users had a risk of fibroids comparable with never users (OR 1.1, 95% CI 0.9-1.4). The risk of uterine fibroids decreased with duration of oral contraceptive use: compared with never users, the estimated OR was 0.8 (95% CI 0.5-1.2) in ever users for four to six years and 0.5 (95% CI 0.3-0.9) for seven years or more (chi2 trend = 4.6, P = 0.03).
  
  
  CONCLUSIONS
  Although the role of selection bias should be carefully evaluated, the present data suggest that uterine fibroids should not be considered a contra-indication for oral contraceptive use.
authors.affiliation: Mario Negri Institute, Milan, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Chiaffarino
authors.forename: F
authors.initials: F
authors.lastname: Parazzini
authors.forename: C
authors.initials: C
authors.lastname: La Vecchia
authors.forename: S
authors.initials: S
authors.lastname: Marsico
authors.forename: M
authors.initials: M
authors.lastname: Surace
authors.forename: E
authors.initials: E
authors.lastname: Ricci
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003276:Contraceptives, Oral / Q000009:adverse effects*; D004522:Educational Status; D005260:Female; D006801:Humans; D007889:Leiomyoma / Q000139:chemically induced*; D008393:Marriage; D008875:Middle Aged; D017697:Premenopause; D018570:Risk Assessment; D012307:Risk Factors; D014594:Uterine Neoplasms / Q000139:chemically induced*
chemical_list: D003276:Contraceptives, Oral