Immune thrombocytopenic purpura (ITP) is an autoimmune disorder with its highest frequency in young women in the reproductive years. An antepartum diagnosis of maternal thrombocytopenia has become more common because platelet counts are now included with routine complete blood cell counts. Sometimes platelet autoantibodies facilitate increased platelet destruction by the reticuloendothelial system especially the spleen. These autoantibodies (IgG) can cross the placenta and place the fetus at risk for thrombocytopenia and, sometimes, serious bleeding problems such as intracranial hemorrhage can occur. The treatment is performed by corticosteroids (prednisone) or intravenous immune gammaglobulin. Four patients with thrombocytopenia during pregnancy underwent medical treatment (prednisone 1 mg/kg/die). The results were successful. In one case only we did not have a clinical response after corticosteroid therapy. There were no intracranial hemorrhages; however the risk for the patients and fetal or neonatal hemorrhage is much lower than thought. Corticosteroid treatment is the first choice, but sometimes it can give a clinical negative response.