Coagulation in the First Five Days of Life

Abstract

Comprehensive coagulation studies were made in 15 normal newborn infants on the first, third and fifth days of life. Platelet counts, whole blood clotting times, and clotting times of recalcified plasma were normal. At this stage of life the blood is hypercoagulable in vitro. An abnormal prothrombin time was found on the first day of life only. The prothrombin consumption index was invariably abnormal on the first day and tended to become normal by the fifth day. Thromboplastin generation was abnormal throughout the period. Antihemophilic globulin activity was generally normal, but plasma thromboplastin component activity was generally low. Minor coagulation defects in the newborn appear to be due to deficiencies of stable factors such as PTC, Stuart-Prower factor and factor VII.