Essential thrombocythemia/polycythemia vera and pregnancy: the need for an observational study in Europe.

The management of pregnant patients with essential thrombocythemia (ET) and polycythemia vera (PV) may be problematic. In the literature there are approximately 300 cases of pregnancies reported in ET and less than 50 pregnancies reported in PV. To reduce the effect of reporting bias, we selected articles with either > 10 pregnancies or at least six patients, and here report on the outcome of 195 pregnancies in ET and 36 pregnancies in PV patients.