The coagulation system of extremely preterm infants: influence of perinatal risk factors on coagulation

Abstract

Objective: Little is known about the influence of preterm delivery and perinatal risk factors on development and expression of the coagulation system in extremely preterm infants. The objective of this study was to determine reference values for the components of the coagulation system at the first day of life in extremely preterm infants.Study Design: Components of the coagulation system were examined retrospectively in 132 extremely preterm infants. Patients were grouped according to clinical criteria for preterm delivery: group A: maternal indication; group B: uteroplacental dysfunction; group C: systemic inflammation.Result: Levels of coagulation factors VII and X rose with increasing gestational age, whereas fibrinogen and coagulation factors II, V and VIII remained constant. Levels of factors V and VIII were higher than those of vitamin K-dependent factors. If preterm delivery was caused by placental disorder (group B) or chorioamnionitis (group C), levels of factor II, VIII and X were significantly lower, whereas factor V and VII levels did not differ. In group C fibrinogen levels in group C were higher compared with group A. Conclusion:Identification of perinatal risk factors may help to define patients at risk of bleeding disorders.

Effect of Promoter Polymorphisms on Cytokine Concentration in Preterm Breast Milk and Subsequent Infant Outcomes

“…IL6 crosses the blood–brain barrier 39 and has procoagulative properties. 40,41 In addition, IL6 activation decreases vitamin K-dependent coagulation factors and subsequent IVH development. 40 Neurodevelopmental complications among infants who experience IVH are lessened if they received breast milk.…”

Reference intervals for common coagulation tests of preterm infants (CME)

“…First, identifying a coagulation value as “abnormal” depends on having accurate reference intervals for comparison. Reference intervals for late preterm and term infants are available, but meager data are found for preterm infants . This is due, in part, to the large amount of blood needed for these tests relative to the patient's blood volume and the difficulty in obtaining blood samples that are reliably uncontaminated by heparin.…”

“…It has been postulated that coagulation studies can be of value in managing preterm neonates who appear to be at risk for intraventricular (brain), pulmonary, or gastrointestinal hemorrhage . Indeed, some neonatologists advocate routinely drawing coagulation studies from preterm neonates upon admission to the neonatal intensive care unit (NICU) and prophylactically administering fresh‐frozen plasma (FFP) if certain abnormalities are identified . Neonatologists who do not routinely follow this practice cite the problems of the relatively large volume of blood required for testing and the difficulty obtaining blood samples uncontaminated by heparin .…”

Laboratory Coagulation Parameters in Extremely Premature Infants Born Earlier than 27 Gestational Weeks upon Admission to a Neonatal Intensive Care Unit

“…Current reference ranges used in this institution for coagulation profiles in infants of all gestational ages (GA) are based on data previously published [4] and acted as a comparison group for data in this study. Previous studies aiming to characterize reference ranges for coagulation parameters in extremely premature infants have been limited by small sample sizes overall (n = 10 [15], n = 21 [16], n = 52 [17]) and inclusion of very few infants <26 weeks' gestation [8,9,10] or examined a limited number of coagulation factors [18]. …”