Pregnancy loss and thrombophilia: the elusive link.

Recurrent pregnancy loss (RPL) affects 1% pregnancies and is multi-factorial in origin. The role of the acquired thrombophilia antiphospholipid syndrome (APS) as a common and potentially treatable cause of RPL is well established but this is less so for inherited thrombophilia. In obstetric APS the combination of aspirin and heparin has improved outcomes. By analogy, the use of low molecular weight heparin (LMWH) has become commonplace in women with inherited thrombophilia and also those with unexplained miscarriage to help safeguard the pregnancy. This review will examine the pathophysiological role of thrombophilia in pregnancy loss, and the evidence for anticoagulant-based intervention. The limited data supporting the use of heparin for women with RPL and inherited thrombophilia suggests adoption of a more cautious and judicious approach in this setting.