Perinatal management of idiopathic thrombocytopenic purpura in pregnancy: risk factors for passive immune thrombocytopenia.

Thirty-nine pregnant women with idiopathic thrombocytopenic purpura (ITP) were studied in order to evaluate the influence of therapies for maternal ITP on fetal passive immune thrombocytopenia (PIT). Neonatal platelet counts were also compared with platelet counts, amount of PAIgG, and presence of circulating antiplatelet antibody in maternal blood. Eight of 41 neonates (19.5%) presented PIT without neonatal mortality. A higher incidence of PIT was observed in women with prior splenectomy than in women without splenectomy (66.7% vs 11.4%). Neither a therapeutic effect nor an increased risk of PIT was observed with steroids or gammaglobulin administration. No correlation was found between neonatal platelet counts and maternal platelet counts or maternal PAIgG, while positive cases for circulating antiplatelet antibody assay presented a higher incidence of PIT than negative cases. Additionally, a higher incidence of PIT was observed in women with a history of previous PIT than in women with a history of normal delivery. Prior splenectomy, presence of antiplatelet antibody in maternal blood, and a history of previous PIT seem to be risk factors for fetal PIT.