Antenatal management of fetal and neonatal alloimmune thrombocytopenia: Integration of clinical history and maternal HLA-DRB3*01:01 genotyping in clinical decision-making.

BACKGROUND

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare but potentially life-threatening condition caused by maternal alloantibodies against paternally inherited fetal human platelet antigens (HPA), most commonly HPA-1a. The condition may result in severe thrombocytopenia, with the most serious complication being intracranial hemorrhage (ICH). Effective risk stratification and antenatal management are essential to mitigate adverse outcomes in subsequent pregnancies.

CASE PRESENTATION: We present three cases of HLA-DRB3*01:01 positive pregnant women with a history of FNAIT in previous pregnancies. Antenatal therapy included weekly intravenous immunoglobulin (IVIG) in combination with corticosteroids, initiated between 14 and 20 weeks of gestation. All three pregnancies resulted in the birth of healthy neonates without signs of ICH or clinically significant thrombocytopenia. Notably, despite the differences in the initiation of antenatal therapy with immunoglobulins and corticosteroids, clinical outcomes were favorable across all cases.

CONCLUSION

These cases highlight the clinical value of integrating detailed clinical history and maternal HLA-DRB3*01:01 genotyping to stratify risk and guide antenatal management. Early initiation of IVIG therapy, appropriate dose adjustment, and multidisciplinary care in specialized centers are key components in optimizing perinatal outcomes in FNAIT.