The bleeding neonate

The neonate is born with a combined deficiency in plasma coagulation factors, natural inhibitors of haemostasis and components of the fibrinolytic system. In the healthy neonate, there is a balance between haemostatic systems, therefore under normal circumstances, the healthy neonate does not present haemorrhage or thrombosis. However several coagulation disorders, congenital or acquired, may be expressed during the neonatal period in a healthy or diseased neonate. Haemophilia A, B (Haem-A, B) and von Willebrand disease (vWD) are the most common inherited coagulation disorders, whereas congenital deficiencies of FI, FII, FV, FVII, FX, FXI, FXII or FXIII occur rarely. Cephalematoma, intracranial haemorrhage (ICH), bleeding from the umbilicus cord may be the first signs of congenital FXIII, FVII or FVIII deficiency. Acquired coagulation plasma factors deficiency is usually associated with vitamin K deficiency (early, classic, late haemorrhagic disease, secondary haemorrhagic disease), liver insufficiency (hepatitis, metabolic diseases e.t.c) or disseminated intravascular coagulation, complicating severe sepsis. Platelets are produced from the 11th gestational week of the foetus. The healthy neonate, full-term or premature, is born with a normal platelet value (>150x109/L). Any value <100x109/L should be investigated. Thrombocytopenia is frequent in the neonatal period (0.7-0.9%), whereas it occurs in 20-40% of patients in a neonatal intensive care Unit. 20-40% of the cases are of unknown aetiology. Congenital quantitative (Tarr, Wiskott-Aldrich syndrome, amegakaryocytic thrombocytopenia, Alport syndrome, Fanconi’s anaemia, vWD type II, Mediterranean megathrombocytopenia, Flechtner syndrome, Sebastian anomaly, Trousseau syndrome, Chediak-Higashi syndrome) or qualitative platelet disorders (Glanzman, Bernard-Soulier syndrome, May Hegglin anomaly), are rare. On the contrary, acquired thrombocytopenias or thrombasthenias occur more often. Thrombocytopenia due to increased platelet destruction is usually associated with several diseased states (bacterial/viral infections, fungal or protozoal infections) or an immune mechanism (autoimmune, isoimmune thrombocytopenia). The risk of ICH is higher in neonates with isoimmune thrombocytopenia. Finally, secondary thrombasthenias are most often associated with antibiotics anti-inflammatory drugs, anti-histamines, indomethacin e.t.c. Haemostasis screening includes thrombin time, prothrombin time, APTT, platelet count, clot retraction and bleeding time. Further investigation unmasks the defect and determines the necessity and type of therapeutic intervention, taking under consideration the bleeding manifestations and infant’s clinical condition.