First‐Trimester Molecular Screening for Fetal and Neonatal Alloimmune Thrombocytopenia: Early Identification of At‐Risk Pregnancies
Sebastián Blanco, Luis Horacio Carrizo, José María Lazarte, Laura Carina Vega, Jorge Mario Culaso, Sandra Verónica GallegoABSTRACT
Objective
The aim of this study was to evaluate the feasibility and clinical value of implementing first‐trimester molecular HPA screening to identify pregnancies at risk for FNAIT.
Methods
In this prospective cohort study, pregnant women were genotyped during the first trimester for HPA‐1, ‐2, ‐3, ‐4, ‐5, ‐6, ‐9, and ‐15 using molecular methods. When low‐frequency maternal genotypes were identified, paternal genotyping and risk stratification were performed to assess maternal–fetal incompatibility. At‐risk pregnancies underwent structured clinical monitoring, and neonatal platelet counts were obtained at birth.
Results
Among 200 screened pregnancies, three (1.5%) were HPA‐1b/1b. Prenatal screening identified five pregnancies at risk for FNAIT: three involving HPA‐1, one HPA‐3, and one HPA‐15 incompatibility. Two neonates required compatible platelet transfusions. Early detection allowed anticipatory perinatal management and facilitated timely transfusion support when indicated.
Conclusions
First‐trimester molecular HPA screening is feasible and enables an early identification of pregnancies at risk for FNAIT across multiple antigen systems, allowing for appropriate clinical interventions. These findings support the potential role of targeted prenatal screening programs in improving the recognition and management of FNAIT, even in populations with a low prevalence of HPA‐1a–negative women.