Fetal and neonatal alloimmune thrombocytopenia in pregnancies involving in vitro fertilization: A report of four cases

Objective We report four cases of neonatal alloimmune thrombocytopenia (NATP) in pregnancies achieved with in vitro fertilization. Study design Three cases used surrogate carriers, and the fourth a donor egg. Sera from gestational carriers were tested for platelet antibodies by flow cytometry and enzyme-linked immunosorbent assay. Platelet antigen genotyping of biologic mothers, fathers, and surrogates was performed by amplification of DNA by using polymerase chain reaction with sequence-specific primers. Results In all 4 cases, NATP resulted from an incompatibility between the fetus and gestational carrier for the platelet-specific alloantigen HPA-1a. Four infants were born severely thrombocytopenic (platelets <50,000/μL), 2 had antenatal intracranial hemorrhage, and 1 fetus expired in utero at 29 weeks. Conclusion NATP can occur in the setting of assisted reproductive technology. Because of the great costs, both financial and emotional, associated with these pregnancies, we strongly recommend that all women be typed for HPA-1a before serving as a surrogate mother.