A review of the contemporary management of fetal and neonatal alloimmune thrombocytopenia in an Australian tertiary obstetric hospital

Abstract

Background: Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is the most common cause of severe perinatal thrombocytopenia, arising from the transplacental passage of maternal antibodies directed at paternally inherited antigens on fetal platelets.

Aim: To review the occurrence, management and perinatal outcomes of pregnancies complicated by FNAIT from a single tertiary obstetric hospital in Western Australia.

Materials and methods: The study was conducted as a retrospective review of cases with prenatally recognised FNAIT between 2001 and 2011, with the treatment modalities and outcomes analysed.

Results: Over the 10-year period, 20 cases of clinically significant FNAIT in 13 women were managed at our centre. Three cases were complicated by antenatal intracranial haemorrhage (15%), and in all 3, this was the presenting feature leading to diagnosis. In 17/20 (85%) cases, anti-HPA 1a was the responsible antibody, with the remainder being anti-HPA 5b. In 16/17 cases with pre-pregnancy recognition, intravenous gammaglobulin (IVGG) was administered antenatally (gestation at commencement ranging from 13 to 26 weeks) with adjuvant prednisolone in three cases. Postnatal treatment (IVGG or platelet transfusion) was provided in 4/16 cases. There was no intracranial haemorrhage or demise in any case receiving prenatal therapy.

Conclusions: FNAIT is a rare and serious condition. In our small single-centre study, there was variability in the therapeutic strategies, although IVGG was central to all prenatally managed pregnancies. None of the treated pregnancies was complicated by intracranial haemorrhage or fetal death. There is a need for ongoing refinement of FNAIT management protocols, both in the prenatal and in the postnatal period.