RESUMO
OBJECTIVES: To study the prevalence of anemia among healthy infants, and outcomes of giving a therapeutic trial of iron to anemic infants in thalassemia-endemic area. METHODS: A cross sectional study was conducted in 6-9-month-old, full-term healthy infants who attended the well child clinics at 2 tertiary care centers in southern Thailand. Complete blood count and serum ferritin were performed in every infant, and hemoglobin typing was performed only in anemic cases. All anemic infants were given a therapeutic trial of iron and categorized into either; iron responder (hemoglobin increased ≥ 1 g/dL) or iron non-responder (hemoglobin increased <1 g/dL) groups after one month of the therapeutic trial. Mean levels of hematological parameters, including the Mentzer index, were compared within the groups. RESULTS: A total of 620 infants were included in the study. From this, 230 infants (37%) were anemic for which iron deficiency contributed for 80% of the etiology. The iron responder group showed significant improvement in hematological parameters after a trial of iron, while there was no improvement in the iron non-responder group. Among iron responders, there were 31 out of 186 infants (16.6%) who had coexisting abnormal hemoglobin typing, and their post-treatment complete blood count still showed a mean corpuscular volume < 70, with a Mentzer index < 13. CONCLUSION: Iron deficiency remains a major cause of anemia among infants, and a therapeutic trial of iron is beneficial in this age group, even though thalassemia trait/hemoglobinopathy can co-exist.