A single institutional experience with 43 pregnancies in essential thrombocythemia

OBJECTIVES: We describe the periconception circumstances and outcome of 43 consecutive pregnancies in an unselected group of young women with essential thrombocythemia (ET). PATIENTS AND METHODS: We retrospectively studied 74 consecutive cases of young women with ET seen at our institution, among whom 43 pregnancies occurred in 20 patients. Results: Of the 43 pregnancies, 22 (51%) were successful (21 term and 1 preterm live births) and 21 (49%) ended in miscarriages (1 ectopic pregnancy, 2 elective abortions, 16 first-trimester spontaneous abortions, 1 stillbirth at 22 wk, and 1 abruptio placentae at 33 wk). Management of ET at the time of conception included either no specific therapy (16 cases) or the use of aspirin alone (24 cases), a cytoreductive agent (2 cases), or heparin (1 case). There were no significant differences with respect to platelet count or the effect of treatment with aspirin, either at the time of conception or during the first trimester, among cases of successful pregnancies (22), all miscarriages (21), or first-trimester spontaneous abortions (16). The findings were similar when the analysis was restricted to only first-time pregnancies. In patients with multiple pregnancies, the outcome of a subsequent pregnancy was not predicted by the outcome of the first. In general, in successful cases the last two trimesters were mostly uneventful, with healthy offspring being reported in all cases. Conclusions: Pregnant patients with ET have an increased risk of first-trimester abortion which is not predictable by preconception platelet count or aspirin therapy. In addition, our experience does not support the use of prophylactic platelet apheresis during delivery.