Fetal and Neonatal Alloimmune Thrombocytopenia: Harvesting the Evidence to Develop a Clinical Approach to Management

Neonatal alloimmune thrombocytopenia (NAIT) is the most common cause of severe thrombocytopenia in an otherwise healthy newborn. The most serious complication is intracranial hemorrhage, which can occur either in the fetus or the newborn. Despite the known serious sequelae, both antenatal management and neonatal treatment modalities are plagued by the lack of gold standard evidence to appropriately direct therapy. Maternal, risk-based therapeutic approaches range from invasive protocols to relatively benign noninvasive strategies to avoid serious procedural complications. Intravenous immunoglobulin (IVIG) with or without steroids and fetal blood sampling constitute the mainstay of antenatal management. Neonatal interventions principally focus on the use of antigen-negative compatible or random donor platelets and IVIG. While awaiting the results of controlled trials, each institution must develop a standardized, collaborative, multidisciplinary approach to the screening, diagnostic evaluation, and management of unexpected and anticipated NAIT based on experience, product availability, and emerging scientific data.