ORIGINAL ARTICLE Effects of gestational age and prenatal and perinatal events on the coagulation status in premature infants

Objective: To study prospectively the effects of prematurity and perinatal events on the coagulation status of premature infants. Patients and main outcome measures: Blood samples from premature infants born before 37 gestational weeks were taken for analysis of coagulation factors II, V, VII, and X and platelet count. Results: A total of 125 premature infants, 71 boys, were studied at the median postnatal age of 40 minutes (range 12–100). The lowest median activities of coagulation factors II, V, VII, and X and the platelet count were observed, as expected, in infants (n = 21) born at 24–27 weeks gestation. Twin B (n = 14) had lower median activities of coagulation factors II, V, VII, and X than twin A. Infants with evidence of mild asphyxia (Apgar score at 5 minutes < 7 or cord pH < 7.26) had significantly (p < 0.05) lower levels of coagulation factors II, V, VII, and X and platelet counts than infants without asphyxia. Infants who were small for gestational age (SGA) had significantly (p < 0.05) lower levels of coagulation factors V and VII and platelet counts than infants of appropriate size for gestational age. Other prenatal and perinatal variables examined (sex, maternal hypertension and/or pre-eclampsia, antenatal steroid use, mode of delivery, Apgar scores) did not show any significant associations with coagulation status, which may be explained by the small number of infants studied