Prevalence of Iron Deficiency and Iron Deficiency Anemia in Exclusively Breastfed Term Infants in a Tertiary Hospital in Thailand Using the WHO Revised Criteria for Anemia

Objective: To assess the prevalence and associated factors of iron deficiency (ID) and iron deficiency anemia (IDA) in term exclusively breastfed (EBF) infants using the new 2024 Hb cutoff, and to study iron supplementation in Thai pediatricians’ clinical practice. Materials and Methods: A retrospective chart review included healthy term EBF infants for ≥ 6 months from January 2014 to July 2022. Blood samples collected between 6 and 12 months were analyzed for CBC and serum ferritin (SF) levels. IDA was defined as Hb level < 10.5 g/dL and SF < 12 ng/ml, and ID was defined when SF < 12 ng/ml but Hb ≥ 10.5 g/dL. Results: Of the 204 participants, 59.8% were female and mean age at blood collection was 9.4 months. Using 2024 criteria for anemia, the prevalence of ID and IDA was 11.3% and 10.3%, respectively. Daily iron supplementation was provided to 10.3% of infants, with the median dose of 1.23 mg/kg/day. No statistically significant risk factors (sex, birth order, birth weight, maternal age, numbers of maternal underlying conditions, receiving iron supplementation, liver paste consumption after age 6 months, and growth status) for ID or IDA were identified. Supplemented infants had significantly higher levels of Hb and SF. Conclusions: Using the new criteria, ID and IDA are still prevalent. Most pediatricians do not routinely prescribe iron medication for EBF infants. Supplemented infants demonstrated more favorable Hb and SF levels. The potential role of iron supplementation to prevent ID and IDA during infancy in resource-limited countries should be emphasized.