Risk of iron deficiency at 6 months in predominantly breastfed infants with normal iron status and latent iron deficiency at birth

Objective To assess the prevalence of iron deficiency in predominantly breastfed infants at 6 months of age and compare the risk of iron deficiency between those born with latent iron deficiency (LID) and those with normal iron status (NIS). Methods This prospective cohort study was conducted at a single tertiary care center in southern India. Infants born at a gestational age of more than 34 weeks were enrolled and classified based on their cord serum ferritin concentrations as having either NIS (ferritin > 75 ng/mL) or LID (ferritin 11-75 ng/mL). At 6 months of age, these infants were reassessed for hemoglobin and serum ferritin levels to evaluate their iron status. Results Of 559 neonates included, 45 had LID and 514 had NIS at birth. At 6-month follow-up, 272 infants were reassessed: 33 with LID and 239 with NIS. The mean hemoglobin at 6 months was 10.21 ( +/- 1.14) g/dL in the LID group and 10.48 ( +/- 0.96) g/dL in the NIS group. The overall incidence of iron deficiency was 27.6%. The incidence was significantly higher in the LID group (48.5%) compared to the NIS group (24.7%), with a relative risk of 2.3 (95% CI: 1.48, 3.56), and a p-value of < 0.001. Conclusions Predominantly breastfed infants with LID at birth are at a significantly higher risk of developing iron deficiency by 6 months of age compared to those with NIS at birth. Early screening and timely iron supplementation in infants with LID may help mitigate iron deficiency.