Hydroxyurea in two pregnant women with sickle cell anemia

Hydroxyurea is classified as an S-phase antineoplastic agent (pregnancy cat egory D). Two women became pregnant while taking hydroxyurea for sickle cel l anemia and delivered live infants with no congenital anomalies. Although teratogenic effects of hydroxyurea were reported in animal studies, several case reports suggest the agent :may have minimal teratogenic effects on th e developing fetus. Fourteen cases of hydroxyurea therapy in pregnant patie nts with acute or chronic myelogenous leukemia, primary thrombocythemia, or sickle cell disease are reported in the literature. Three pregnancies were terminated by elective abortion; one woman developed eclampsia and deliver ed a phenotypically normal stillborn infant. All other patients delivered l ive, healthy infants without congenital anomalies. Further studies with lar ger numbers; of patients receiving hydroxyurea during pregnancy, with longe r follow-up of exposed children and more careful assessment of fetotoxic ef fects, are required before the agent can be promoted as safe in pregnancy.