31 Iron Deficiency in Formula-fed Very Preterm Infants: Do We Need to Revise Recommendations for Iron Supplementation?

Abstract

Abstract Background Preterm infants are at risk for iron deficiency (ID). The Canadian Paediatric Society (CPS) recommends iron supplementation of 2 to 3mg/kg/day for breastfed (BF) preterm infants born <2 kg. Additional iron supplementation is not recommended if these infants are primarily formula-fed (FF) with iron-rich formula, since formula is thought to provide enough iron. However, these recommendations are not universally accepted. Objectives To investigate how feeding type influences the iron status of very preterm infants (VPI) at 4 to 6 months corrected age. Design/Methods A retrospective population-based cohort study was conducted using a provincial database of all VPI (<31 weeks gestational age) born in Nova Scotia from 2005-2018. Information about feeding type, iron intake from formula, and supplemental iron therapy at 4- to 6-month follow-up was extracted, as were neonatal variables. Two groups were compared using chi-square and unpaired t-tests. Results 392 infants were studied (gestational age: 23-30 weeks). Of these, 285 were exclusively FF with iron-rich formula, and 107 were exclusively or partially BF. Neonatal variables were comparable between the two groups. An elemental iron intake of >2 mg/kg/day was obtained from formula alone in only 20.4% of FF infants. FF infants were less likely to receive additional iron supplements. However, total iron intake (from formula and supplements) was higher in FF infants. Despite this, 36.8% of infants in FF group developed ID, versus 20.6% in the BF group (Table 1). Conclusion Most VPI fail to receive elemental iron of >2 mg/kg/day from formula alone. ID is significantly more prevalent in FF infants than in BF infants, despite higher iron intake. Our findings do not support the current CPS guidelines.