Background: Preterm neonates are at high risk of iron deficiency due to low iron store at birth. Recent research has shown a link between low iron stores in neonates and poor neurocognitive outcome. Serum ferritin is often used as a measure of iron stores in neonates that require phlebotomy.
Objective: To investigate the potential use of urinary ferritin as non-invasive screening method for evaluating iron reserve in preterm neonates without the need for phlebotomy.
Patients and Methods: Paired blood and urine samples were collected from 35 preterm neonates enrolled in this cross-sectional study on first day of life.
Measurement of urine ferritin was done using ELISA while, serum ferritin and urine creatinine were assessed by routine laboratory assay. The included neonates were consequently identified as either normal or deficient iron storage groups according to a predefined minimal serum ferritin value of 35 ng/mL approved for preterm and low birth weight neonates
Results: The median concentrations of serum and urinary ferritin were 230ng/mL and 154ng/mL, respectively. urinary ferritin concentrations correlated positively with gestational age, birth weight and serum ferritin concentrations. Urinary ferritin concentrations and urine ferritin/creatinine ratio were found significantly lower in the deficient iron storage group as compared to the normal iron storage group. A cut-off value for urinary ferritin of ≤50 ng/mL had a sensitivity83.3 %and a specificity96.5% for indication of iron storage deficiency with a PPV83.3%.
Conclusion: Urinary ferritin levels in preterm neonates could be a feasible non-invasive screen for iron deficiency in preterm neonates since low values could identify iron store depletion.