To characterize standard laboratory coagulation parameters and plasma thrombin generation in very preterm infants and to investigate their relationship to clinical outcomes

Very premature infants are at risk of bleeding and frequently given plasma because of perception that coagulation tests are abnormal, which may simply be due to immaturity. We hypothesized that characterization of coagulation tests alongside assessment of thrombin generation would provide information on preterm haemostasis. In a prospective observational study, cord and peripheral blood was drawn from neonates Between 2013 - 2015, 137 infants Preterm cord blood peak thrombin and endogenous thrombin potential were similar to controls (132 (40.6) nM vs. 136.7(35) nM; p=0.66 and 1168(289) nM*min vs. 1303 (190) nM*min; p=0.11) respectively (n=27). 20 Mean activity of procoagulant factors II, VII, IX and X (0.31 (0.18-0.5) IU/ml vs. 0.44 (0.35-0.6) IU/ml, p=0.003; 0.33 (0.09-0.57) IU/ml vs. 0.42 (0.31-0.59) IU/ml, p=0.29; 0.16 (0.09-0.5) IU/ml vs. 0.29 (0.19-0.37) IU/ml, p=0.004 and 0.28 (0.13-0.52) IU/ml vs. 0.44 (0.32-0.58) IU/ml, p=0.02) respectively, n=12 and anticoagulant factors Protein C (0.11U/ml (0.06-0.24) IU/ml vs. 0.27 (0.18-0.39) IU/ml; p=0.002), free protein S (0.38 (0.28-0.55) IU/ml vs. 0.47 (0.36-0.59) IU/ml; p=0.02), antithrombin (0.22 (0.06-0.36) IU/ml vs. 0.53 (0.38-0.69) IU/ml; p In conclusion, we describe ranges for coagulation tests, demonstrate differences in both procoagulant and anticoagulant pathways, and show that thrombin generation is similar in very preterm and term infants.