Interaction of the protein C/protein S anticoagulant system, the endothelium and pregnancy.

Normal pregnancy is associated with significant changes in haemostasis, lipid metabolism and endothelial function. This suggests that maternal adaptation in these systems is required for successful pregnancy outcome. A number of acquired and heritable prothrombotic abnormalities are associated with complications in pregnancy. A common feature of these abnormalities is their ability to alter endothelial function or the protein C/protein S system and increase thrombin generation. In this review the normal function of the endothelium and the protein C/protein S system is detailed. The changes which characterize normal and complicated pregnancies are outlined and the evidence for the impact of heritable and acquired disorders of the protein C/protein S system on pre-eclampsia and fetal loss are discussed.