Antiphospholipid syndrome in pregnancy

Purpose of review Antiphospholipid syndrome is widely recognized as a risk factor for numerous obstetric complications including miscarriage, intrauterine growth restriction, preeclampsia, fetal death and preterm labour. The many recent changes in concept regarding this syndrome, the role of the relevant antibodies, mechanism of action, diagnosis and treatment are assessed in this review. Recent findings In recent years, our understanding of antiphospholipid syndrome has grown. The antigen has become better defined and is now thought to be beta2 glycoprotein 1. The 'classical' antibodies, lupus anticoagulant and anticardiolipin antibody are known to be pathogenic even when passively transferred to animal hosts. It seems, however, that the pathogenic antibodies are those directed towards beta2 glycoprotein 1, and that those which are directed to phospholipids without binding to beta2 glycoprotein 1 may not be pathogenic, but merely epiphenomena. The treatment of this condition has also been changed due to the influence of randomized trials in which heparin or low molecular weight heparin has replaced the use of steroids. Summary There are numerous pitfalls in managing this condition. As beta2 glycoprotein 1 antibodies are not usually tested, the condition may be over diagnosed or misdiagnosed. Similarly, the results of treatment are not usually corrected for confounding factors such as fetal chromosomal aberrations. In the absence of other confounding factors low molecular weight heparins are probably the treatment of choice.