A rise in blood platelet count following childbirth or surgical operation is a well established clinical phenomenon and is believed to be a contributory factor in postoperative or postpartum venous thrombosis. This rise begins about the fourth day after operation or delivery and attains its maximum about the tenth day, the number of circulating platelets subsequently falling to the normal by the twenty-first day. The period of hyperthrombocytemia corresponds roughly with the period in which venous thrombosis generally occurs. The correspondence, however, is not complete. To account for this divergence, MacKay1 postulated a second thrombogenic factor, an increased agglutinability or adhesiveness of blood platelets.
A technical method of measuring relative platelet "stickiness," therefore, was developed by Wright2 of Guy's Hospital, London. After addition of an anticoagulant, blood samples are revolved slowly in glass tubes, the rate of decrease in the platelet count being taken as a measure of the
HYPERADHESIVE THROMBOCYTES. JAMA. 1943;122(15):1017. doi:10.1001/jama.1943.02840320035011