Ultraschall Med 2016; 37 - P6_21
DOI: 10.1055/s-0036-1587968

Severe intracranial haemorrhage with cerebral parenchymal necrosis in fetal alloimmune thrombocytopenia – a case report

K Grimm 1, FW Hirsch 2, H Stepan 3, C Kähler 1
  • 1Praxis, Prenatal Diagnosis, Erfurt, Germany
  • 2University Hospital Leipzig, Pediatric Radiology, Leipzig, Germany
  • 3University Hospital Leipzig, Obstetrics, Leipzig, Germany

Purpose: In fetal/neonatal alloimmune thrombocytopenia (FNAIT) maternal alloantibodies destroy fetal platelets, which harbour the paternal inherited agent (in 80% HPA-1a). The frequency is approximately 1:1000, but FNAIT is supposedly highly underdiagnosed. In contrast to rhesus incompatibility, this disease may already occur in the first pregnancy. Since screening is not available, FNAIT is currently not diagnosed before the occurrence of intracranial haemorrhage that may result in lifelong disability or death.

Our case report intends to emphasize the importance of FAIT, especially with respect to future options in prevention and prophylaxis.

Materials and methods: We report on a 29-year-old pregnant woman, IIIG/0P, who was referred to us in week 30 with suspected hydrocephalus. The ultrasound showed an appropriately developed fetus with isolated unilateral hydrocephalus. Hyperechoic intraventricular formations raised the suspicion of intraventricular haemorrhage. Additionally, the cerebral cortex was narrow (9 mm). 3 rd and 4th ventricle and the other brain structures were unremarkable.

Results: Maternal antibodies against HPA-1a were detected and human platelet antigen genotyping of DNA extracted from the amniotic fluid verified the inherited paternal HPA-1a antigen on fetal platelets.

Fetal cMRI confirmed intracranial haemorrhage and revealed cerebral necrosis throughout the middle cerebral artery territory. Due to the poor prognosis and maternal desire the fetal demise was induced. At this time, the child presented a severe thrombocytopenia (11/nl).

Conclusion: FNAIT is considered an important differential diagnosis of intracranial haemorrhage and hydrocephalus and should always be clarified, in particular with regard to therapeutic and preventive measures in the next pregnancy. The potential of a screening program and immune prophylaxis in HPA-1a-negative women, similar to rhesus prophylaxis, will be investigated by the PROFNAIT study and implying a growing importance of FNAIT.