Anemia and iron deficiency in healthy, exclusively breastfed infants: Prevalence and association with sex and birth weight.
Introduction. Anemia and iron deficiency (ID) negatively affect health and neurocognitive development. There is controversy over whether breast milk meets iron requirements between four and six months of age, especially in populations with a high prevalence of anemia. Objective. To determine the prevalence of anemia, ID, and iron-deficiency anemia (IDA) in healthy infants who are exclusively breastfed (EBF), and to analyze their association with sex and birth weight. Population and methods. A retrospective, observational, cross-sectional analytical study. Data were analyzed from healthy infants who received exclusive breastfeeding and were seen at a pediatric center in La Plata from 2013 to 2016. Sex and birth weight (classified as lower birth weight if 2500-2999 g) were recorded. At six months of age, the following were assessed: anemia (hemoglobin <10.5 g/dL), ID (serum ferritin <12 µg/L), and IDA (meeting both criteria). Associations were evaluated, and the odds ratio (95% CI) was estimated using logistic regression (adjusted for sex). Results. A total of 254 infants were included. The prevalence rates of anemia, ID, and IDA were 42.5%, 26.7%, and 13.3%, respectively. The geometric mean ferritin level was lower in boys (p = 0.002). An association was observed between ID and lower birth weight (adjusted OR = 4.45 [95% CI 2.08-9.67]). Conclusion. The prevalence of anemia, ID, and IDA was high. Ferritin levels were lower in male infants. Infants with lower birth weight were more likely to develop DH.