Successful treatment of essential thrombocythemia in a pregnancy with recombinant interferon-alpha 2a.

Essential thrombocythemia (ET) in pregnancy is associated with adverse perinatal outcome, which is likely due to thrombosis of the uteroplacental circulation. Obstetrical management is still controversial. Different therapeutic protocols have been adopted, including the use of aspirin, plateletpheresis, and interferon. We herein report a case of ET treated with interferon-2 alpha from 13 weeks gestation until term. Therapy was well tolerated, leading to a linear reduction of platelet and white blood cell count that rapidly returned within normal limits. A healthy, 3,020-g male infant was delivered at 40 weeks gestation. Albeit further experience is required, recombinant interferon-alpha 2a may play an important role in preventing complications in pregnant patients with ET.