Background: Foetal and neonatal alloimmune thrombocytopenia (FNAIT) is estimated to occur at an incidence of 1:1-2000 live borns, while maternal immunisation against HLA class I is a common finding during pregnancy and after delivery. Whether anti-HLA antibodies can cause FNAIT in some cases is debateable. Aim: This study aims to give a background to FNAIT, and to describe cases of suspected or ...