Introduction: Preterm infants are routinely started on prophylactic iron therapy after birth due to their increased vulnerability to develop iron deficiency (ID). However, some preterm infants may still develop ID despite prophylactic iron supplementation. Timely testing for early diagnosis of ID may have important neurodevelopmental benefits in this high-risk population. Thus, current practice at the IWK is to test all very preterm infants for ID at 4-6 months of corrected age. However, there is a paucity of evidence to support this routine testing for ID.
Objective: To investigate the prevalence of ID and to determine if testing for ID should be routinely performed in preterm infants at 4-6 months corrected age.
Methods: A retrospective cohort study was conducted at the IWK through the provincial Perinatal Follow-Up Program database. All preterm infants (<31 weeks gestational age) born in Nova Scotia were started on prophylactic iron supplements (2-3 mg/kg/day) at 2-4 weeks of age. Iron dosage was regularly adjusted during the NICU stay as guided by serum ferritin levels. At discharge, it was recommended to continue iron prophylaxis until 9-12 months corrected age. All these infants were tested for ID during first neonatal follow-up visit at 4-6 months corrected age. Infants born between 2005- 2018 were included. ID was defined as serum ferritin <20g/l or <12g/l at 4 and 6 months respectively.
Results: Of 411 infants included, 32.1% (n=132) had ID. The prevalence of ID decreased over time (37.6% in 2005-2011 vs 25.8% in 2012-2018 cohort). Table 1 compares the ID and non-ID group.
Conclusion: ID was prevalent in about 1/3 of the preterm infants despite NICU iron prophylaxis. These results elicit the importance of ID testing during preterm follow-up. Further research about risk factors for ID is important to develop practices focused on its prevention and to achieve full neurodevelopmental benefit of prophylactic iron supplementation.
Jon Dorling– Professor, IWK Health Centre
Ketan Kulkarni– Associate Professor, IWK Health Centre
Marsha Campbell-Yeo– Professor, IWK Health Centre
Michael Vincer– Associate Professor, IWK Health Centre
Joyce Ledwidge– Dietitian, IWK Health Centre
Lisa Morrison– Dietitian, IWK Health Centre
Satvinder Ghotra– Assistant Professor, IWK Health Centre