[Autoimmune thrombopenic purpura and pregnancy. Absence of thrombopenia in the newborn infant despite the presence of circulating IgG auto-antibody in the mother].

Many pregnant women with AITP bear children with transient thrombocytopenia which is a potentially life threatening complication. Previous reports have demonstrated that monitoring of IgG circulating platelet antibodies may help with the management of these women. We report the case of a pregnant woman with AITP whose sera contained an IgG auto antiplatelet demonstrated by the fluorescein labelled antiglobulin techniques. Steroids had a beneficial effect with a return to a normal of the mother's platelet count but with no disappearance of the circulating antibody. Surprisingly the neonatal platelet count was normal and studies in the baby showed that the antibody had not crossed the placenta in detectable amounts. This case demonstrates our current inability to predict fetal thrombocytopenia and plan the mode of delivery.