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.