Key learning points
FNAIT is rare but a potentially disastrous condition.
Management should focus on prevention of ICH.
The majority of ICH occurs during intrauterine life.
There is a lack of good quality evidence to guide management.
The index pregnancy is the most important factor for risk estimation of ICH.
Maternal IVIG administration appears to reduce risk of ICH even when the platelet count shows no response.
References
1.Williamson LM, Hackett G, Rennie J, et al. The natural history of fetomaternal alloimmunization to the paltelet-specific antigen PA-1a (PIA1, Zwa) as determined by antenatal screening. Blood 1998; 92: 2280–7.
2.Serrarens-Janssen v M, Steegers EA, van den Bos A, et al. Experiences with fetomaternal alloimmune thrombocytopenia in the Netherlands over a 2-year period. Acta Obstetrica et Gynecologica Scandinavica 2005; 84: 203.
3.Knight M, Pierce M, Allen D, et al. The incidence and outcome of fetomaternal alloimmune thrombocytopenia: a UK national study using three data sources. Br J Haematol 2011; 152: 460–8.