Noninvasive antenatal management of fetal and neonatal alloimmune thrombocytopenia: safe and effective

Objective To describe the outcome of pregnancies with fetal and neonatal alloimmune thrombocytopenia (FNAIT) in relation to the invasiveness of the management protocol. Design Retrospective analysis of prospectively collected data from a national cohort. Setting Leiden University Medical Centre, the national centre for management of severe red cell and platelet alloimmunisation in pregnancy. Population Ninety‐eight pregnancies in 85 women with FNAIT having a previous child with thrombocytopenia with (n= 16) or without (n= 82) an intracranial haemorrhage (ICH). Methods Our management protocol evolved over time from (1) serial fetal blood samplings (FBS) and platelet transfusion (n= 13) via (2) combined FBS with maternal intravenous immunoglobulins (n= 33) to (3) completely noninvasive treatment with immunoglobulins only (n= 52 pregnancies, resulting in 53 neonates). Perinatal outcome was assessed according to the three types of management. Main outcome measures Occurrence of ICH, perinatal survival, gestational age at birth and complications of FBS. Results All but one of 98 pregnancies ended in a live birth; none of the neonates had an ICH. The median gestational age at birth was 37 weeks (range 32–40). In groups 1 and 2, three emergency caesarean sections were performed after complicated FBS, resulting in two healthy babies and one neonatal death. Conclusion Noninvasive antenatal management of pregnancies complicated by FNAIT appears to be both effective and safe.