Pregnancy in Women With Immune

\s=b\Thirty-six women with immune thrombocytopenic purpura were studied during 37 pregnancies, and maternal characteristics with predictive value for the fetal platelet count were determined. Nine neonates were thrombocytopenic, with a platelet count of less than 50 \m=x\ 109/L in eight. Four of these nine neonates delivered to a subgroup of 31 mothers were studied prospectively; the frequency of thrombocytopenia in neonates of women with immune thrombocytopenic purpura was thus 13%. Only two of these nine neonates presented with hemorrhagic syndromes (two, petechial purpura; one, intracranial bleeding). The frequency of neonatal thrombocytopenia was higher in mothers with deep thrombocytopenia and in those who had not responded to corticosteroid treatment following diagnosis. No prognostic value could be assigned to the other maternal characteristics studied, such as a history of splenectomy, maternal treatment at the time of delivery, or the presence of platelet autoantibodies evaluated either with the platelet immunofluorescence test or the platelet Western blot immunoassay. (Arch Intern Med. 1990;150:2141-2145) Tmmune thrombocytopenic purpura (ITP) is a frequent platelet disorder that is usually due to the presence of an IgG platelet autoantibody.1 The predominance of the disease in women ofchildbearing age2 and the increased disease activ¬ ity during pregnancy, particularly in women with a compen¬ sated thrombocytolytic state,2 explain why active ITP is fre¬ quently associated with, or discovered during, pregnancy. The IgG platelet autoantibody can actively cross the placenta and may induce fetal or neonatal thrombocytopenia.3 Lifethreatening intracranial bleeding with possible long-term neurologic consequences can complicate the neonatal throm¬ bocytopenia.2 Previous studies have reported the frequency of thrombocytopenia to be around 50% in these neonates,3'* with a perinatal mortality of about 20%.2,7"9 Vaginal delivery is particularly dangerous for thrombocytopenic neonates on ac¬ count of the fetal cranial compression that could favor bleeding.2 The obstetric management of women with ITP remains controversial. Steroids and high-dose intravenous immuno¬ globulins are frequently administered in an attempt to correct the maternal thrombocytopenia. Great efforts have been made to predict the fetal platelet count and thus avoid vaginal delivery for thrombocytopenic neonates and needless cesarean sections for nonthrombocytopenic neonates.3,6,10,11 Howev¬ er, no definite predictive criteria have yet been established. We report the clinical and biologic analysis of a group of 36 pregnant women with ITP. This study was undertaken to determine (1) the frequency of neonatal thrombocytopenia in a subgroup of 31 pregnant women studied prospectively, and (2) maternal characteristics with predictive value for the neonatal platelet count. Biologic techniques, in particular the platelet Western blot immunoassay, were used to improve the characterization of the platelet autoantibodies.