Essential thrombocythemia and pregnancy.

A review of the literature disclosed 106 pregnancies (preg.) in 57 women with essential thrombocythemia (ET). The success rate (baby alive) was 57% (60 live births/106 preg.), the rate of miscarriage 43% (46 miscarriages/106 preg.). The most frequent complication was spontaneous abortion during the first trimester in 36% (38 abortions/106 preg.). Other complications such as intrauterine death and stillbirth after the 28th week, which occurred in 5% (7/106), premature delivery in 8% (8/106), pre-eclampsia in 4% (4/106), and fetal growth retardation in 4% (4/106) were rarer events. Placental infarction due to thrombosis seems to be the most consistent pathological event as far as the fetus is concerned. Maternal hemorrhage occurred in 4% (3 minor and 1 major bleeding) and only 2 minor maternal thrombotic episodes have been observed. Interestingly, a decline in platelet count has been observed in 14 women and was associated with a successful preg, in 13/14 cases (93%). Aspirin (ASS) was the most frequently used drug in 47 of 93 recorded cases (51%). In 16 evaluable women treated with ASS the live birth rate was higher (12/16 preg., 75%) than for 21 untreated women (9/21 preg., 43%). In 5 cases interferon alpha (IFN) has been used successfully. In summary, 57% of women with ET had a live birth, maternal complications happened in 6%. Promising treatment modalities might be ASS and IFN. However, no definitive answer can be given on the ideal management for women with ET during pregnancy. A European register should be set up.