Do thrombophilias cause placenta-mediated pregnancy complications?

There has been an sudden increase of knowledge about thrombophilias in the last decade as new thrombophilias are discovered and new associations are explored. It is now evident that thrombophilias are common and that the clinical consequences of having a thrombophilia do not appear to be limited to venous thromboembolism. The placenta-mediated pregnancy complications are also common (more than one in six pregnancies are affected) and include pregnancy loss, preeclampsia, placental abruption, and intrauterine growth restriction. These complications as a whole are the leading causes of maternal and neonatal morbidity in the developed world. Evidence has emerged to suggest that thrombophilic women may be at higher risk of developing these placenta-mediated pregnancy complications. However, is this evidence mature enough to claim that a causal association is proven? Is the evidence strong enough to recommend anticoagulant prophylaxis? We suggest that causality is not yet proven and that the data to support management with anticoagulant prophylaxis in thrombophilic pregnancies is too immature to consider this an established intervention.