A Study of Coagulation Factor Levels in Women during Labour and in Their Newborn Infants

Abstract

Summary1. Coagulation factors levels were measured in 10 normal mothers and in their infants within 15 min of birth and at 48-96 hrs of age.2. In the mothers the levels of fibrinogen (532 mg/%), factors VIII (196%), IX (130%) and X (122%) were elevated; the levels of prothrombin (107%) and factor V (108%) were normal ; and the level of factor XI (69%) was reduced.3. The infants blood examined within 15 min of birth had a slightly elevated factor VIII level (138%), slightly reduced fibrinogen (195 mg/%) and factor V levels (79%), low levels of prothrombin (55%) and factors IX (27%), X (35%) and XI (32%).4. Blood from the infants at 48-96 hrs of age showed little change from the birth levels of factors V (89%), and VIII (116%) and a slight increase in factor XI level (39%). Four of the infants had received vitamin K1 and had higher levels of prothrombin and factors IX and X than the 7 who had not received vitamin K1.5. These results are compared with those of previous studies and the possible mechanisms underlying the changes is discussed.