Alloimmune neonatal thrombocytopenia and hydrocephalus. Platelet antigen Zwa, ABO-antigens and HLA-antigens in mothers to infants with hydrocephalus.

In 27 mothers to infants with hydrocephalus determinations of platelet antigen Zwa, HLA-typing and ABO-typing were performed in order to evaluate whether undiagnosed alloimmune neonatal thrombocytopenia (AINT) could be an aetiological factor in hydrocephalus. All mothers were Zwa-positive, and the frequency of HLA-antigens and ABO-antigens was as in the normal population. Though sporadic cases of hydrocephalus following AINT are reported, this is not a common cause of intracranial haemorrhage and hydrocephalus.