Abstract

ABSTRACT Background.Screens for anemia are among the most commonly done laboratory tests in children. The red cell distribution width (RDW) has been proposed as a diagnostic aid in the evaluation of pediatric anemias, but no prospective studies have been published describing its use. Methods.A screening hematocrit determination done at the 12-month well-baby examination in 970 healthy infants yielded 62 low values (<33%), 31 of which were confirmed by heel stick complete blood count (CBC). After a 1-month trial of iron therapy, those with a rise in hemoglobin of at least 1 g/dL were considered to have iron-deficiency anemia. Nonresponders, after review of clinical and laboratory data (CBC, lead screen, and sickle screen), had hemoglobin electrophoresis if indicated. Results.Abnormalities detected were iron deficiency, α-thalassemia, and hemoglobins SC and AS. These conditions were detected in 9 of 11 infants with abnormal RDW and none of 9 with normal RDW. Conclusions.The RDW alone appears to be predictive of identifiable causes of anemia when used in screening 12-month-old babies who are otherwise healthy.