High prevalence of anemia in 10-month-old breast-fed Japanese infants.

Background: Anemia in infancy is still prevalent in developing countries. Commercial iron-fortified complementary foods or iron drops are not available in Japan, and breast-fed infants have a higher risk of anemia. We studied anemia screening in 10-month-old infants to determine whether breast-feeding is a risk factor for anemia.

Methods: Anemia screening was performed during regular health check for 10-month-old children at four local pediatric clinics in Shimane Prefecture, Japan. Venous blood was obtained for complete blood count. The clinical characteristics of each child were obtained via questionnaire. Anemia was defined as hemoglobin <11.0 g/dL. Children were categorized into anemia and no-anemia groups, and univariate analysis was conducted on comparison of the clinical variables. Multivariate logistic regression analysis for anemia was performed to adjust for several clinical variables.

Results: We analyzed data in 325 children. On univariate analysis, anemia was associated with breast-feeding, monthly bodyweight gain and gestational week. On multivariate logistic regression analysis, anemia was associated with feeding type and gestational week (OR of partial breast-feeding and formula feeding, 0.446; 95%CI: 0.208-0.957; and 0.223; 95%CI: 0.075-0.660, respectively, compared with exclusive breast-feeding, OR, 1.0; and gestational week, OR, 0.753; 95%CI: 0583-0.972).

Conclusion: Breast-feeding is an important factor for anemia in 10-month-old Japanese infants. Breast-fed infants after 6 months of age may need iron supplements or iron-fortified complimentary foods.