A low birth weight infant with no malformations delivered by a primary immune thrombocytopenia patient treated with eltrombopag.

Primary immune thrombocytopenia (ITP) is defined by a low platelet count secondary to antibody-mediated platelet destruction or reductions in platelet production. Although eltrombopag is a thrombopoietin receptor agonist that increases platelet production in refractory or relapsed ITP, the influence on pregnancy is limited. We present the case of a pregnant 25-year-old ITP patient referred to our hospital with a history of two induced abortions. After eradication of Helicobacter pylori and with oral prednisolone at 8 mg/day, platelet count remained below 10,000/µl. Because she declined splenectomy, eltrombopag was initiated at 12.5 mg/day. Afterward, platelet count was maintained at over 50,000/µl. Twenty-one months later, pregnancy became apparent. She continued treatment, and cesarean section was performed at 37 weeks of gestation after administration of intravenous immunoglobulin, platelet transfusions, and steroids. The baby weighed only 1670 g but showed no malformations, and platelet count at birth was 416,000/µl. Studies of eltrombopag in pregnancy have not been reported. A case with administration of eltrombopag from the last trimester of pregnancy that resulted in low birth weight has been reported. Embryo lethality and reduced fetal weights have been reported from animal experiments. Further investigation about the relationship between low birth weight deliveries and eltrombopag is necessary.