title: Risk of thrombosis associated with oral contraceptives of women from 97 families with inherited thrombophilia: high risk of thrombosis in carriers of the G20210A mutation of the prothrombin gene.
abstract: OBJECTIVE
  Oral contraceptives (OC) and inherited thrombophilia are well-known risk factors associated with venous thromboembolism (VTE). However, there are only few studies on the risk of VTE in women with inherited thrombophilia who use oral contraceptives.
  
  
  METHODS
  We performed a retrospective family cohort study of 325 women belonging to 97 families with inherited thrombophilia, including antithrombin, protein S and C deficiencies, the factor V Leiden mutation (FVL) and the G20210A mutation of the prothrombin gene (PT20210A) to determine the risk of VTE associated with OC intake.
  
  
  RESULTS
  For carriers of the PT20210A mutation, the risk of VTE in OC users was 3-fold higher (95% CI 1.3-6.8) than that in non-carriers. Carriers of FVL mutation taking OC showed an OR of 1.4 (95% CI 0.6-3.3), indicating a tendency to increase the risk of VTE.
  
  
  CONCLUSIONS
  Because of the high prevalence of the PT20210A (6.5%) and FVL (2%) mutations in the general Spanish population and the increased risk of VTE associated with OC intake, genetic screening for these mutations should be considered in potential OC users belonging to families with thrombophilia.
authors.affiliation: Thrombosis and Haemostasis Unit, Haematology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Santamaría
authors.forename: J
authors.initials: J
authors.lastname: Mateo
authors.forename: A
authors.initials: A
authors.lastname: Oliver
authors.forename: B
authors.initials: B
authors.lastname: Menéndez
authors.forename: J C
authors.initials: JC
authors.lastname: Souto
authors.forename: M
authors.initials: M
authors.lastname: Borrell
authors.forename: J M
authors.initials: JM
authors.lastname: Soria
authors.forename: I
authors.initials: I
authors.lastname: Tirado
authors.forename: J
authors.initials: J
authors.lastname: Fontcuberta
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003276:Contraceptives, Oral / Q000009:adverse effects*; D005192:Family Health; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D013030:Spain / Q000453:epidemiology; D019851:Thrombophilia / Q000150:complications / Q000235:genetics*; D013927:Thrombosis / Q000139:chemically induced* / Q000209:etiology / Q000235:genetics
chemical_list: D003276:Contraceptives, Oral