Vitamin K status of preterm infants with a prolonged prothrombin time

Abstract
To investigate the vitamin K status of preterm infants who have a prolonged prothrombin time (PT) in the first month of life. Measures of vitamin K status were assessed in 21 preterm infants who were found to have an abnormal PT, despite 0.2-0.5 mg vitamin K(1) prophylaxis at birth. All infants had normal or supraphysiological vitamin K(1) concentrations and undetectable or, in one infant, insignificant PIVKA-II, indicating adequate vitamin K status. In preterm infants born at or = 0.2 mg vitamin K(1) after delivery, a prolonged PT in the first month of life is unlikely to be due to vitamin K deficiency.