[Platelet transfusions in neonatology].

Thrombocytopenia occurs in 20% to 40% of infants admitted to a neonatal intensive care unit. Approximately 30% of the newborns with severe thrombocytopenia below 50.10(9)/l platelets receive platelet transfusions. The etiology may be: bacterial infection, DIC and immune mediated thrombocytopenia. The consequences of thrombocytopenia are significant risks of severe intracranial hemorrhage and neurologic morbidity. Therapeutic platelet transfusions are given to actively bleeding neonates with less than 50.10(9)/l platelets. Prophylactic platelet concentrates are usually given to infants with platelets counts below 20.10(9)/l. The standard platelet concentrate (CMV-negative donor) is the product of choice for newborns. Fetal intracranial hemorrhage is possible as soon as 20 weeks of gestation in allo-immune thrombocytopenia. Actually percutaneous umbilical blood sampling is very useful to measure fetal platelets count in order to decide in utero maternal platelet transfusion. Maternal irradiated plateletpheresis concentrates are preferentially infused in this indication. At the end of pregnancy, cesarean section is preferred to normal vaginal delivery if fetal thrombocytopenia below 100.10(9)/l is observed. In pregnant women with auto-immune thrombocytopenia, the decision to carry out percutaneous umbilical blood samples should be weigh relatively to the 3-5% estimated risk of serious consequences. Platelets transfusions are particularly successful in immune thrombocytopenia but less effective in other clinical circumstances.