Aim: To analyse the course of pregnancy in chronic myeloproliferative diseases (CMPD) with hyperthrombocytosis, primarily, essential thrombocytemia.
Material and methods: The analysis of thrombogenic risk factors covered literature data and 8 cases observed by the authors.
Results: Six pregnant women received long-term treatment with preparations of interferon-alpha in a dose 9-20 million IU a week (both before and during pregnancy). Rapid reduction of hyperthrombocytosis (1100-4000 x 10(9) l) and the absence of a negative effect on development of the fetus were seen in all the cases. Normal delivery on week 37-39 was in 4 patients, spontaneous abortion on week 24 was provoked by a car accident. Three gravidas (gestational week 28, 33 and 34) are still under observation. Lupus anticoagulant or elevation of anticardiolipin antibodies level was detected in 4 of 8 patients, 2 patients had heterozygous mutation of methylentetrahydrofolatereductase genes and factor V (Leiden). These patients were given lannacher, faxiparine, folic acid and discrete plasmapheresis (in 2 cases).
Conclusion: Gravidas with hyperthrombocytosis, if not contraindicated, must be treated with aspirin and interferon-alpha preparations at any gestational term. Moreover, it is necessary to exclude additional most prevalent causes of thrombophilia for adequate prevention of thromboses.