Management of pregnancy in women with thrombophilia.

Hereditary thrombophilia increases the risk of thrombosis during pregnancy and postpartum. The recommendations resulting from the Fifth American College of Chest Physicians (ACCP) Consensus Conference on Antithrombotic Therapy were published in Chest in late 1998. However, levels of evidence on this subject were low (C2). Furthermore, since publication of this ACCP consensus, new studies have demonstrated the safety of low-molecular-weight heparins (LMWHs) in pregnant women. In addition, it is now clear that all thrombophilias are not associated with the same level of thrombotic risk: factor V Leiden mutation and factor II 20210A variant are associated with a lower risk than antithrombin deficiency. Consequently, the ACCP recommendations have been reconsidered in the light of a more widespread use of LMWH and taking into account the differences in the level of risk of the different thrombophilias. A prophylaxis of thrombosis in pregnant women with thrombophilia is proposed based on published data and our personal experience. Although laboratory monitoring is usually not required during treatments with LMWH, it seems to be needed in pregnant women who receive long-term treatments.