[The Prevalence of Iron Deficiency Anemia Among 6- to 18-month-old Children in Japan]

Background: Iron deficiency anemia is one of the treatable causes of developmental delay in infants and is therefore screened in several countries. However, in Japan, a screening program for anemia among infants has not been introduced and data on the prevalence of iron deficiency anemia and results of therapeutic trial with iron supplementation are limited.

Objective: To examine the prevalence of anemia, diagnosis was made with venipuncture blood and iron deficiency anemia was confirmed in a therapeutic trial of infants in Japanese communities.

Participants: Six- to 18-month-old infants participated in the anemia screening program in Shinshiro city and Shitara districts, Aichi, and Fujisawa town, Iwate, Japan.

Methods: Capillary blood samples in microtubes were obtained by skin puncture, and centrifuged to measure the hematocrit. When the value was low, venipuncture blood was examined. A hemoglobin concentration under 11 g/dl was judged as a positive result. Anemic infants were referred to pediatrics for prescription of ferrous sulfate. Iron deficiency anemia was defined as a hemoglobin concentration elevated by 1 g/dl or more with a 4-week regimen of ferrous sulfate (therapeutic trial).

Results: Of 283 eligible infants, 161 were screened (participation rate, 57%). Mean (SD) microhematocrit by skin puncture was 35.9(2.2)%. Thirteen infants (8%, 95% Cl: 4 to 13%) were anemic, and 7 infants (4%, 95% Cl: 2 to 9%) demonstrated iron deficiency anemia in the therapeutic trial. There was no significant difference between study sites in mean microhematocrit, and prevalence of anemia or iron deficiency anemia.

Conclusions: The prevalence of anemia and iron deficiency anemia among infants in the study communities is high enough to warrant considering routine screening. Further studies are needed to determine whether a high prevalence of anemia is widespread in Japan.