Background and aims Iron deficiency (ID) has long-term detrimental effects on neurodevelopment. Preterm infants are at risk for developing ID or iron deficiency anaemia (IDA) during the first weeks of life. The aim of this study was to identify early risk factors during hospitalisation for a deprived iron status in late preterm infants at the age of 6 weeks.

Methods We analysed the iron status of 99 infants born between 32 and 35 weeks of gestational age from March 2011 to May 2013 in three non-tertiary hospitals in the Netherlands. ID and IDA at the age of 6 weeks were defined as a ferritin concentration <70 µg/L and the combination of a haemoglobin level < 110 mg/dL and ID, respectively.

Results ID and IDA at 6 weeks were present in 34% and 28% of the infants, respectively. Until now risk factors for ID were collected in 63 infants (shown in table 1). Multivariate regression analysis showed that ID at the age of 6 weeks was associated with a lower birth weight, a lower serum ferritin at the age of 1 week (p = 0.013) and a higher number of blood draws during hospitalisation (p = 0.018). IDA was also associated with the number of blood draws (p = 0.023). ID and IDA were not associated with mean iron intake.

Conclusion ID and IDA are quite common among late preterm infants at the age of 6 weeks. Risk factors include a low birth weight, a lower serum ferritin at 1 week and a higher number of blood draws during hospital stay.