Coagulation problems in the newborn

In order to evaluate newborn infants with bleeding problems, it is necessary to be familiar with the physiology of neonatal hemostasis. Levels of many coagulation factors in healthy fullterm neonates are approximately 50% of the adult mean and are lower in preterm infants. Consideration of the clinical setting and appropriate laboratory tests can differentiate between vitamin K deficiency, disseminated intravascular coagulation, liver dysfunction and congenital coagulation factor deficiencies, thus allowing appropriate treatment to be selected. The use of oral vs intramuscular vitamin K for prevention of late hemorrhagic disease of the new born is discussed.