Objectives To evaluate the safety of vaginal delivery in pregnancies with fetal and neonatal alloimmune thrombocytopenia (FNAIT).
Design Prospective data collection.
Setting Leiden University Medical Centre, the national centre for management of severe red cell and platelet alloimmunisation.
Population Thirty-two pregnancies with FNAIT, with a sibling with thrombocytopenia but without an intracranial haemorrhage (ICH).
Methods The mode of delivery, platelet count in cord blood and neonatal outcome were analysed. All women received weekly intravenous immunoglobulin from 32 to 38 weeks of gestation. Head ultrasound scan was performed in all neonates.
Main outcome measures Signs of ICH or other bleeding in the neonates.
Results Twenty-three women delivered vaginally. Nine caesarean sections were performed, all for obstetric reasons. Median platelet count at birth was 142 × 109/l (range, 4–252 × 109/l), with severe thrombocytopenia (<50 ×109/l) in four neonates, of which three were born vaginally. None of the neonates showed signs of ICH or other bleeding.
Conclusions In pregnancies with FNAIT and a thrombocytopenic sibling without ICH, vaginal delivery was not associated with neonatal intracranial bleeding. These initial results support our noninvasive management of these pregnancies with FNAIT.