32 Risk Factors for Iron Deficiency in Formula-fed very Preterm Infants: A Population-based Study from Nova Scotia

Abstract

Abstract Background Iron prophylaxis is routinely recommended for preterm infants, as they are vulnerable to develop iron deficiency (ID). Recent work from our group has demonstrated that despite early iron prophylaxis, ID is common in very preterm infants (VPI), with an incidence of 32% at 4 to 6 months corrected age (CA). Additionally, ID is more prevalent in exclusively formula-fed (FF) VPI compared to infants who are exclusively or partially breast-fed. Objectives To explore the risk factors associated with ID in the FF infants. Design/Methods A retrospective population-based cohort study was conducted using a provincial database. All VPI born in Nova Scotia from 2005 to 2018 who were exclusively fed with iron-rich formula (>10 mg/L) at 4 to 6 months CA were included. Information about formula type, iron intake from formula, and supplemental iron therapy at 4- to 6-month follow-up was extracted, as were neonatal variables. ID was defined as serum ferritin <20 and <12 mcg/L at 4- and 6-months CA, respectively. Results ID was present in 36.8% (105) of 285 FF infants. Table 1 shows key characteristics of ID and non-ID FF infants. Mean gestational age and birth weight were lower in the ID group. More babies in the ID group received blood transfusion (Odds:1.1-3.0). Other maternal and neonatal variables were comparable between the groups. ID children did not have a lower iron intake than non-ID children. Conclusion Lower gestational age, lower birth weight, and need for blood transfusions increased the risk of ID in FF infants. Optimal iron supplementation in this population should be guided by a risk-adapted strategy.