Activation of intrinsic coagulation pathway in pre-eclampsia.

Disseminated intravascular coagulation, thrombocytopenia, consumption of factors VIII and II, and antithrombin deficiency have been previously demonstrated in pre-eclampsia. However, the precise mechanism responsible for initiation of disseminated intravascular coagulation has not been elucidated. The present study documents activation of the intrinsic coagulation pathway in a patient with severe pre-eclampsia. The studies revealed marked reductions of plasma coagulant activities of all intrinsic pathway factors, i.e., XII, XI, IX, and VIII. In addition, the ratio of plasma factor XII activity to antigen concentration was markedly abnormal, and plasma high-molecular-weight kininogen concentration was diminished. It is suggested that activation of the intrinsic coagulation pathway may be operative in the genesis of disseminated intravascular coagulation in pre-eclampsia.