Prenatal diagnosis of fetal intracranial hemorrhage in pregnancy complicated by idiopathic thrombocytopenic purpura.

摘要

Idiopathic thrombocytopenic purpura (ITP) is a relatively common autoimmune disease among women of childbearing age and is characterized by a low platelet count and mucocutaneous bleeding. Consequently, physicians frequently manage pregnant patients with ITP. The incidence of pregnancy complicated by ITP is approximately 0.01 to 0.1% at delivery (ACOG, 1999). ITP is caused by IgG antiplatelet autoan-tibodies that recognize platelet membrane glycopro-teins. IgG-coated platelets are rapidly cleared from the circulation by the reticuloendothelial system, mainly by splenic macrophages through their Fc receptors (Sukenik-Halevy et al., 2008). During pregnancy, maternal IgG antiplatelet autoantibodies can cross the placenta and induce fetal or neonatal thrombocytopenia (ACOG, 1999). Of infants born to women with ITP, about 10 to 12% has a platelet count less than 50000/ uL with 4 to 5% having a platelet count less than 20000/ uL (Sukenik-Halevy et al, 2008). Occasionally, neonatal thrombocytopenia leads to minor bleeding complications such as petechiae, ecchymoses and melena. On the contrary, major bleeding events such as intracranial hemorrhage (ICH) or severe gastrointestinal hemorrhage are rare (ACOG, 1999; Gill and Kelton, 2000). Because the platelet count of the affected infant usually declines after delivery and the nadir occurs after several days, a prenatal fetal hemorrhagic event is extremely rare, and almost hemorrhagic events actually occur after birth (ACOG, 1999; Kelton, 2002). The incidence of ICH of infants born to a mother with ITP is less than 1% and there are no reports of ICH clearly proven to have occurred before or during delivery (Sukenik-Halevy et al., 2008). This frequency of neonatal ICH due to maternal ITP is quite low compared to neonatal alloimmune thrombocytopenia (NAIT). With NAIT, there is a 10 to 20% ICH rate and 25 to 50% of ICH occurs prenatally (Bussel, 1997).