Essential thrombocythemia associated with recurrent abortions and fetal growth retardation.

Essential thrombocythemia (ET) is one of the myeloproliferative disorders characterized by an elevated platelet count, usually greater than 1,000 X 10(9)/L. It may be associated with either hemorrhagic or thrombotic tendencies. Although it usually affects older people, we have recently encountered two young women with ET who had a total of six spontaneous abortions before the end of the first trimester. During her most recent pregnancy, one of the patients underwent plateletpheresis on four separate occasions before the 12th week. She reached 34 weeks but demonstrated evidence of fetal growth retardation and pre-eclampsia. At delivery there were scattered villus infarcts in the placenta. Based on this patient and previous reports in the literature, we postulate that the spontaneous abortions, fetal growth retardation, and pre-eclampsia may be related to the thrombocytosis and suggest that the use of antiplatelet agents throughout pregnancy should be seriously considered in such cases.