Abstract

The coagulation system of neonates undergoes significant change during the perinatal period. Concentrations of most coagulation factors and anticoagulants are lower in the healthy term newborn than in the normal adult, but there is a physiological balance that prevents abnormal coagulation. This balance may be disrupted by prematurity, or acute perinatal stressors such as hypoxia, predisposing the neonate to bleeding or thrombosis. In this prospective study, the authors have looked at the influence of maternal age and ethnicity, mode of delivery and intrapartum events – duration and augmentation of labour, presence of meconium, instrumental delivery – gender and weight on the neonatal coagulation system. Women were recruited antenatally if they had a singleton pregnancy, no known medical or bleeding disorder and normal blood pressure. Cord blood was collected at delivery if gestation was 37 weeks or more (n=159). Factor (F) VIII:C, VWF:Ag, VWF:CB, FIX:C, FXI:C and FXII:C were significantly higher in those who went through active labour regardless of mode of delivery compared with those delivered by elective Caesarean section. Maternal age and ethnicity, augmentation or meconium in labour, instrumental delivery, neonatal gender or weight did not appear to affect cord blood factor levels. This implies that the labour process mat have a significant influence on the neonatal coagulation system.