title: Use of selective factor V Leiden screening in pregnancy to identify candidates for anticoagulants.
abstract: OBJECTIVE
  To improve identification of gravidas at risk for thrombosis. Venous thromboembolic complications are a major cause of maternal mortality during pregnancy. Factor V Leiden, which causes activated protein C resistance, is the most prevalent thrombophilia in white populations. However, selective screening for factor V Leiden has not been evaluated previously for identifying women who might benefit from anticoagulant prophylaxis during pregnancy.
  
  
  METHODS
  We constructed a risk score based on major risk factors such as overweight, family history of thrombosis, previous thrombosis, cesarean delivery, and preeclampsia. A cohort of 2384 women with known factor V Leiden status was studied. Using the risk score and its distribution, we explored possible strategies of doing selective testing for factor V Leiden and their consequences.
  
  
  RESULTS
  During the postpartum period, but not antepartum, there is a possibility of identifying women at similar risk as those with a history of thrombosis. Women with a risk score of 2 (4% of women, 0.2% risk of thrombosis) would be screened for factor V Leiden, and those with a resulting risk score of at least 3 (ie, 1.2% risk of thrombosis) would be treated for 6 weeks. Theoretically, for every 83 women treated at this risk level, one thrombotic episode might be prevented.
  
  
  CONCLUSIONS
  By using a risk score, a subgroup of women who could benefit from selective factor V Leiden screening were identified postpartum.
authors.affiliation: Department of Obstetrics and Gynecology, Lund University, University Hospital, Malmö, Sweden. pelle.lindqvist@obst.mas.lu.se
authors.forename: Pelle G
authors.initials: PG
authors.lastname: Lindqvist
authors.forename: Per
authors.initials: P
authors.lastname: Olofsson
authors.forename: Björn
authors.initials: B
authors.lastname: Dahlbäck
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005165:Factor V / Q000032:analysis*; D005260:Female; D006801:Humans; D008403:Mass Screening; D011237:Predictive Value of Tests; D011247:Pregnancy; D011295:Prenatal Care; D011296:Prenatal Diagnosis / Q000379:methods*; D011322:Primary Prevention / Q000379:methods*; D012016:Reference Values; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013548:Sweden; D013927:Thrombosis / Q000097:blood / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D015415:Biomarkers; C095381:factor V Leiden; D005165:Factor V