Neonatal thrombocytopenia: Etiology and management

Neonatal thrombocytopenia is defined as a platelet count of less than 150 x 10 9/L. Approximately 15% of healthy infants will have a platelet count of 100-150 x 109/L. Neonates with platelet counts of less than 100 x 109/L, require investigation. Thrombocytopenia is a risk factor for significant hemorrhage, adverse neurodevelopmental outcome and mortality. Early signs and symptoms may include petechiae and mucosal bleeding. The first step in investigating neonatal thrombocytopenia is to check the maternal platelet count. If this is abnormal screening should be initiated for maternal diseases such as immune thrombocytopenia (ITP), systemic lupus erythematosis (SLE) or hyperthyroidism. If maternal platelets are normal, neonatal alloimmune thrombocytopenia (NAIT) or other neonatal disorders should be explored. The etiology of known neonatal disorders that result in thrombocytopenia generally include one of four categories: increased platelet consumption, decreased platelet production, increased destruction or a variable combination of the three mechanisms. The pathophysiology of increased platelet consumption encompasses a wide spectrum of conditions such as disseminated intravascular coagulopathy (DIC), thrombosis, hemangioma, polycythemia, intrauterine growth restriction (IUGR), or may occur following an exchange transfusion. Conversely, decreased platelet production is usually due to aplastic anemia, leukemia, neuroblastoma or other congenitally acquired syndromes. Asphyxia and metabolic disorders are generally ascribed to combined mechanisms. The etiology of thrombocytopenia may also be related to the time of occurrence. Early-onset or fetal thrombocytopenia is often associated with placental insufficiency. This form of thrombocytopenia is generally benign and is associated with a spontaneous recovery in the absence of other complications such as sepsis. Thrombocytopenia diagnosed less than 72 hours of birth may be due to NAIT or ITP and congenital infections, while aneuploidy or congenital/inherited thrombocytopenias should also be considered as part of the differential diagnosis. Late onset thrombocytopenia develops rapidly and is almost always a result of underlying sepsis or necrotizing enterocolitis (NEC). The platelet nadir is reached within 24-48 hours, and is followed by a slow recovery with treatment over 1-2 weeks. Other less common causes include: inherited disorders (Bernard-Soulier syndrome, May-Hegglin anomaly, and Type II Vonwillebrand disease), bone marrow disorders (i.e. congenital leukemia, Langerhan's cell histiocytosis, neuroblastoma), or giant hemangioma. The primary steps in the management of neonatal thrombocytopenia are: identification of the most likely cause of the thrombocytopenia, management specifically tailored to the cause as in NAIT, and appropriate administration of platelet transfusions. While a safe lower limit to trigger a platelet transfusion has not been defined, prophylactic platelet transfusion is normally considered for a platelet count of less than 30 x 109/L, and less than 50 x 109/L for a very sick or premature infant. There are currently no evidence-based guidelines for the management of neonatal thrombocytopenia, and these are urgently needed to properly assess appropriate indications for platelet transfusion, the dose and schedule of administration, as well as the short and long term therapeutic effects of the strategy. © 2012 Nova Science Publishers, Inc. All rights reserved.