Lower iron stores were associated with suboptimal gross motor scores in infants at 3–7 months

AIM: To investigate associations between iron status and gross motor scores in infants aged 3–7 months. METHODS: In a prospective study, 252 infants aged 3–7 months were examined using the age‐standardised Alberta Infant Motor Scale (AIMS) prior to analysing iron status in 250 infants. Combined AIMS and ferritin results were assessed in 226 infants, whereas AIMS and reticulocyte haemoglobin (ret‐Hb) results were obtained for 61 infants. We used logistic regressions and receiver operator characteristics to analyse our data. RESULTS: With AIMS z‐score <10th percentile as outcome measure, optimal cut‐off value for ferritin was 51 μg/L (sensitivity 86%, specificity 81%) and 28 pg for ret‐Hb (sensitivity 86%, specificity 85%). The area under the curve for ferritin and ret‐Hb was 0.886 and 0.896, respectively (n = 61). Ferritin <51 μg/L predicted an AIMS z‐score <10th percentile in a logistic regression (OR 3.3, 95% CI 1.4–7.5, p = 0.006, n = 226). Six of 14 (43%) infants with ret‐Hb <28 pg scored <10th percentile on AIMS compared to 1/47 (2.1%) infants with ret‐Hb ≥28 μg/L (Exact, p < 0.001). CONCLUSION: Reticulocyte haemoglobin of <28 pg and ferritin <51 μg/L were associated with suboptimal gross motor scores in infants 3–7 months.