A long-term retrospective study of young women with essential thrombocythemia

To describe presenting clinical manifestations, long-term disease complications, prognostic indicators, and outcome of pregnancy for women younger than 50 years with essential thrombocythemia.

We retrospectively reviewed the records of all patients with essential thrombocythemia evaluated at Mayo Clinic, Rochester, Minn, between 1969 and 1991 and identified 74 young women (median age, 35 years; range, 18-48 years) with essential thrombocythemia. The diagnosis was based on previously established criteria. Median follow-up was 9.2 years (range, 0.2-26.2 years).

Overall survival was similar to that of an age- and sex-matched control population. Thrombotic events (except superficial thrombophlebitis) occurred at and after diagnosis in 11 patients (15%) and 13 patients (18%), respectively. A history of thrombosis at diagnosis was significantly associated with recurrent thrombosis (P = .03). A platelet count higher than 1500 x 10(9)/L at diagnosis was significantly associated with gastrointestinal tract bleeding and subsequent development of venous (but not arterial) thrombosis (P = .04). Major hemorrhagic events occurred in only 3 patients (4%) after diagnosis. Only 1 patient developed acute leukemia. Thirty-four pregnancies occurred in 18 patients. Of these, 17 (50%) resulted in live births. Of the 17 patients with unsuccessful pregnancies, 14 had spontaneous abortions, 1 had an ectopic pregnancy, and 2 had elective abortions. Preconception platelet count, thrombotic history, or specific therapy was not useful in predicting pregnancy outcome.

Young women with essential thrombocythemia can expect long survival with a low incidence of life-threatening thrombohemorrhagic complications or acute leukemia. There is an increased incidence of first-trimester miscarriages that may not be influenced by specific therapy.