Читать книгу Protocols for High-Risk Pregnancies - Группа авторов - Страница 158

Fetal and neonatal alloimmune thrombocytopenia is a maternal alloimmune condition in which specific maternal antibodies target paternally derived HPA expressed on fetal platelets, resulting in potentially severe fetal and neonatal thrombocytopenia. The diagnosis of FNAIT is first suspected based upon a qualifying history of a fetus or neonate with suspected or confirmed thrombocytopenia. A suspected FNAIT diagnosis requires evaluation by parental blood testing, which includes HPA genotyping of both parents. Should a platelet antigen incompatibility be determined within a tested couple, further maternal testing for the presence of antigen‐specific anti‐HPA antibodies is performed to secure a FNAIT diagnosis. Given that disease worsens with successive pregnancies and given that FNAIT‐associated ICH usually occurs prior to labor, antenatal therapy is strongly recommended in all pregnancies complicated by FNAIT to reduce risk for severe thrombocytopenia and related ICH.

A risk‐based noninvasive approach has been developed that we recommend as a management algorithm. This strategy stratifies patients into risk‐based strata based upon clinical history, tailoring treatment regimen intensity based upon past disease severity. Delivery of a pregnancy complicated by FNAIT is generally recommended at 37–38 weeks’ gestational age by cesarean for cases in the medium‐risk category and 35–36 weeks by cesarean for cases in the high‐risk or extremely high‐risk categories. When possible, delivery of a fetus at risk for severe thrombocytopenia due to FNAIT should ideally be coordinated with experienced neonatology and pediatric hematology subspecialists.