The cost effectiveness of empiric intravenous immunoglobulin for the antepartum treatment of fetal and neonatal alloimmune thrombocytopenia

Objective: The purpose of this study was to compare the cost effectiveness of empiric intravenous immunoglobulin (IVIG) with that of fetal blood sampling-indicated treatment for the antepartum care of fetal and neonatal alloimmune thrombocytopenia. Study design: We developed a decision analysis model to compare the cost effectiveness of 2 strategies for treatment of pregnancies in women with a history of fetal and neonatal alloimmune thrombocytopenia and an at-risk fetus: 1) IVIG and corticosteroids as indicated by fetal platelet levels determined by fetal blood sampling (FBS); and 2) empiric IVIG. In the first strategy, FBS is used to measure fetal platelets at 24 weeks of gestation and repeated 6 weeks later to guide pharmacotherapy. In the second strategy, weekly IVIG is empirically administered from 24 weeks' to 37 weeks' gestation. The main outcome measure was the marginal cost per quality-adjusted life years (QALY) gained. Results: For every 1000 women with a fetus at risk for recurrent alloimmune thrombocytopenia, empiric therapy, compared with FBS-indicated treatment, decreases perinatal deaths from 31.7 to 11.8 while increasing the number of infants with long-term neurologic deficits from 6.1 to 9.6. These health outcomes translate to 382 QALYs gained with empiric therapy and a cost effectiveness ratio of $32,747 per QALY favoring empiric therapy. In the sensitivity analysis, empiric therapy was not cost effective when the rate of perinatal ICH exceeded 28%. Conclusion: Empiric IVIG therapy is a cost-effective strategy for the treatment of women at risk for fetal and neonatal alloimmune thrombocytopenia when the rate of perinatal ICH is less than 28%.