title: [Thromboprophylaxis with low-molecular-weight heparin insufficient in high-risk pregnancy].
abstract: OBJECTIVE
  To evaluate the efficacy and safety of thromboprophylaxis with a low of low-molecular-weight heparin (LMWH) in women with an intermediate to high risk of pregnancy-related venous thromboembolism (VTE).
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  We collected data from all pregnant women with an intermediate or high risk of VTE in the period 1996-2009. In accordance with protocol, pregnant women with an intermediate risk of VTE were treated with a prophylactic dose of LMWH for 6 weeks post partum, and pregnant women with a high risk were treated with a prophylactic dose of LMWH during the pregnancy and for 6 weeks post partum. Efficacy was defined as the incidence of VTE during pregnancy or < 3 months post partum, and safety as the incidence of post-partum haemorrhage (PPH) (> 500 ml blood loss) or severe PPH (> 1,000 ml blood loss).
  
  
  RESULTS
  We analysed 34 women (44 pregnancies) with an intermediate risk and 57 women (82 pregnancies) with a high risk of VTE. The incidence of pregnancy-related VTE despite thromboprophylaxis was 5.5% (95% CI: 2.4-12.3). All VTEs occurred in high-risk women, and risk was higher post partum than ante partum: 7.0% (95% CI: 2.9-16.7) and 1.8% (95% CI: 0.4-9.2%), respectively. The risk of PPH was 21.6% (95% CI: 14.3-31.3) and of severe PPH 9.1% (95% CI: 4.7-16.9) and was comparable in women who used LMWH during pregnancy and those who started LMWH post partum.
  
  
  CONCLUSIONS
  There was a considerable risk of pregnancy-related VTE in high-risk women despite a prophylactic dose of LMWH during pregnancy and in the post partum period. For these women thromboprophylaxis with a low, prophylactic dose of LMWH appeared to be insufficient.
authors.affiliation: Erasmus Medisch Centrum,afd. Inwendige Geneeskunde, Rotterdam, the Netherlands. j.roetersvanlennep@erasmusmc.nl
authors.forename: Jeanine E
authors.initials: JE
authors.lastname: Roeters van Lennep
authors.forename: Elvera
authors.initials: E
authors.lastname: Meijer
authors.forename: Frans J C M
authors.initials: FJ
authors.lastname: Klumper
authors.forename: Johanna M
authors.initials: JM
authors.lastname: Middeldorp
authors.forename: Kitty W M
authors.initials: KW
authors.lastname: Bloemenkamp
authors.forename: Saskia
authors.initials: S
authors.lastname: Middeldorp
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D006473:Postpartum Hemorrhage / Q000453:epidemiology; D049590:Postpartum Period; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000453:epidemiology / Q000517:prevention & control*; D018566:Pregnancy, High-Risk; D012189:Retrospective Studies; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000453:epidemiology / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight