Objectives: To test whether an increased iron dose is associated with improved neurodevelopment as assessed by the Bayley Scales of Infant Development (BSID-III) among infants enrolled in the Preterm Erythropoietin (Epo) Neuroprotection Trial (PENUT).
Study design: This is a post hoc analysis of a randomized trial which enrolled infants born at 24 to 28 completed weeks of gestation. All PENUT infants who were assessed with BSID-III at 2 years were included in this study. The associations between enteral iron dose at 60 and 90 days and BSID-III component scores were evaluated using generalized estimating equations models adjusted for potential confounders.
Results: 692 infants were analyzed (355 placebo, 337 Epo). Enteral iron supplementation ranged 0-14.7 mg/kg/day (IQR 2.1-5.8 mg/kg/day) at day 60, with a mean of 3.6 mg/kg/day in placebo-treated infants and 4.8 mg/kg/day in Epo-treated infants. A significant positive association was seen between BSID-III cognitive scores and iron dose at 60 days, with an effect size of 0.77 BSID points per 50 mg/kg increase in cumulative iron dose (P = .03). Higher iron doses were associated with higher motor and language scores, but did not reach statistical significance. Results at 90 days were not significant. The effect size in the Epo-treated infants compared with placebo was consistently higher.
Conclusion: A positive association was seen between iron dose at 60 days and cognitive outcomes. Our results suggest that increased iron supplementation in preterm infants, at the doses administered in the PENUT Trial, may have positive neurodevelopmental effects, particularly in infants treated with Epo.