Management of Philadelphia negative chronic myeloproliferative disorders in pregnancy.

The management of pregnancy in Philadelphia negative chronic myeloproliferative disorders (CMPDs) is an increasingly frequent problem. In the literature, most pregnancies are reported for women with essential thrombocythemia (ET) with about 400 pregnancies in about 200 women. In ET, first trimester abortion is the most frequent complication occurring in about one third of pregnancies. Interestingly, the incidence of maternal complications is relatively low with 3% for major thromboembolic and 2% for major bleeding events. The presence of the Jak2 mutation seems to be an independent predictor of pregnancy complications. Pregnancies in ET should be stratified according to underlying risk factors in low, high and highest risk pregnancies. Women with low risk pregnancies are treated with low-dose aspirin, whereas women with high and higher risk pregnancies may benefit from low-dose aspirin plus interferon alpha +/- low molecular weight heparin throughout pregnancy and at least for six weeks post-partum. In polycythemia vera (PV) there is only very few information on pregnancy outcome with 36 pregnancies reported in the literature. According to these data pregnancy in PV is per se a high risk situation. Accordingly, all women with PV should be treated with low-dose aspirin. Some pregnant PV patients may benefit from a more intensive therapy including interferon alpha +/- low molecular weight heparin throughout pregnancy and at least for six weeks post-partum.