Chronic myelocytic leukemia and the myeloproliferative diseases during the child-bearing years.

Chronic myelocytic leukemia and the myeloproliferative diseases may present as asymptomatic elevations of peripheral blood counts or with relatively nonspecific symptoms. Full diagnostic evaluation is necessary to eliminate the many other causes of blood count elevation. Coincidence of a myeloproliferative disease and pregnancy is unusual. The pregnancy has no adverse effect on the course of the mother's hematologic disease. However, the myeloproliferative diseases, especially if uncontrolled, result in increased fetal prematurity and mortality. Treatment of the pregnant patient should be conservative, and cytotoxic therapy should be avoided until at least after the first trimester whenever possible. Busulfan has been the drug most widely used during pregnancy, and it appears not to cause fetal malformations when used alone.