[Pregnancy in patients with essential thrombocythemia. Three cases].

The authors report 3 pregnancies in 3 patients with essential thrombocythemia. In the 3 cases, the course of the pregnancy was successful, with normal delivery in 2 cases, and premature delivery of a live fetus because of an abruptio placentae in the third case. From these 3 cases and a review of the literature, the authors analyse the fetal and maternal risks of pregnancy in these patients and the potential usefulness of preventive treatments (platelet antiaggregating drugs, anticoagulants). Besides, in these 3 cases a steadily decrease in blood platelet counts was observed during pregnancy with a nadir just before delivery followed by a sharp increase in the days following delivery. These findings may give some useful information on the regulation of thrombopoiesis.