Platelets, coagulation, and the liver

This chapter reviews platelets and their function and the coagulation system during normal pregnancy as well as with the preeclampsia syndrome. In addition, the central role of the liver and hepatic dysfunction is described. It has been apparent for almost a century that the coagulation system is in some way involved in the pathogenesis of preeclampsia. Pathological study of specimens taken from the organs of women dying with this disease revealed the presence of fibrin deposition and the formation of thrombi in the microcirculation. Whilst only 10-20% of pregnancies complicated by preeclampsia have evidence of abnormal liver function tests, these pregnancies tend to have a more severe form of the disease. Thus we describe not only the pathophysiology of the hepatic and coagulation cascades in preeclampsia, but the synergistic effect between the two systems that results in the development of HELLP (Hemolysis, Elevated Liver function tests, Low Platelets) syndrome.