Coagulation Disorders In The Neonate

141 <Abstract Coagulation disorder in neonates is a term which refers to both bleeding andthrombosis. To understand it we must know the normal physiology of hemostasis andBlood Coagulation.Normally in the blood, there are pro-coagulants (responsible for coagulation of theblood) and anticoagulants (responsible for fluidity of the blood), but the anticoagulantsnormally predominate, so that the blood doesn’t coagulate while it is circulating in theblood vessels. Whenever a vessel is severed or ruptured, hemostasis (coagulationsystems) is started to stop bleeding by several mechanisms to form a blood clot.The main components of the hemostasis process are the vessels wall, platelets,coagulation proteins, and anticoagulant proteins. Another important component forhemostasis process is fibrinolytic system which causes limitation of clot formation andalso lyses of blood clot to re-establish the vascular integrity.The components of the coagulation and fibrinolytic systems are similar innewborns, older children and adults. However, plasma concentrations of thesecomponents in newborns differs markedly from children and adults and change frombirth through infancy but they increase rapidly after birth, reaching adult levels of mostcomponents by six months of age.Thrombosis occurs more frequently in the neonatal period than at any other age inchildhood. The greatest risk factor for arterial or venous thrombosis is the presence of anindwelling vascular catheter but there are also other risk factors such as geneticpredisposition (hemostatic prothrombotic defects) and environmental or other clinicalconditions.