Screening Primiparous Women and Newborns for Fetal/Neonatal Alloimmune Thrombocytopenia: A Prospective Comparison of Effectiveness and Costs

Abstract

A prospective study was conducted in three maternity wards to compare the medical outcomes and the costs of two screening strategies for the detection of fetal/neonatal alloimmune thrombocytopenia (FMAIT). A total of 2066 primiparas and 6081 newborns were included. Fifty-two primiparous women with HPA-1b phenotype were found, and 45 were followed during pregnancy. Four women developed antibodies, and two fetuses exhibited FMAIT; therefore, the prevalence of anti-HPA-1a was 2 per 1000, and the prevalence of FMAIT 1 per 1000. Forty-eight thrombocytopenic newborns were found out of a total of 5632 blood samples. Five were HPA-1a children whose mothers were HPA-1b. The cost-effectiveness of screening all primiparous women was $45,000 and of screening all newborns is $18,000-per anti-HPA-1a alloimmunization diagnosed. Costs per fetal death or disability averted were $500,000 for the primiparous strategy and $225,000 for the newborn strategy. In conclusion, screening newborns for neonatal alloimmune thrombocytopenia is more cost-effective than screening primiparous women.

A screening and intervention program aimed to reduce mortality and serious morbidity associated with severe neonatal alloimmune thrombocytopenia

“…The 6 prospective studies 24,25,28,29,31,32 in which platelet counts were obtained from the neonates immediately after delivery may reflect the natural history of NAIT better than the other prospective studies 7,8,[21][22][23]26,27,33,34 in which pregnant women were HPA 1a typed, because different interventions were employed in many of the latter studies. A comparison with the first group may therefore be more relevant in order to examine whether implementation of our screening and intervention program reduces the number of serious complications to severe NAIT.…”

“…Many of the previously published prospective studies 8,[26][27][28][29]34 have used a more proactive strategy with FBS and intrauterine transfusions. We decided not to use such a strategy because of the increased risk of fetal death associated with FBS in pregnancies complicated by fetal thrombocytopenia.…”

“…35 It is also noteworthy that serious complications of FBS were reported in 4 of the 6 prospective studies that used this procedure as part of their strategy. 8,[27][28][29] Our more conservative approach using CS a few weeks prior to term seemed to be associated with less NAITassociated complications than more proactive strategies.…”

Neonatal alloimmune thrombocytopenia

“…1 Mild to moderate hyperhomocysteinemia has emerged as an independent cardiovascular risk factor, 4,5,6 probably associated with endothelial dysfunction, and may exert unfavorable effects on the antithrombotic properties of the endothelium. 2 Finally, recent research adds support to the view that atherosclerosis is an inflammatory process. 3 The acute coronary syndrome usually results from erosion or rupture of a vulnerable atherosclerotic plaque leading to acute coronary occlusion.…”

“…2,3 The most feared complication is intracranial hemorrhage (ICH) in the case of severe thrombocytopenia. The morbidity has been estimated to be 20% of the reported cases and mortality up to 15%.…”