Abstract
Four additional cases of leukemia associated with pregnancy are reported. Pregnancy does not alter the course of either acute or chronic leukemia. A leukemic mother has never given birth to a leukemic baby; the disease has never been known to pass the placental barrier. Termination of pregnancy by therapeutic abortion serves only to produce a non-viable baby; it does not benefit the mother. Caesarean section to save the baby is justifiable when near term and when the mother is near death. Pregnancy need not alter the usual measures of therapy for leukemia with the exception that forms of X-ray irradiation should be used with caution to prevent injury to the fetus.