Summary: Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a disease caused by allo-immunisation during pregnancy. If left untreated, FNAIT can lead to severe fetal intracranial haemorrhage. This complication can be prevented by weekly administration of intravenous immunoglobulin (IVIg) to the mother during pregnancy. Knowledge on long-term development of FNAIT survivors with or without IVIg treatm...