Impact and interactions between risk factors on the iron status of at-risk neonates.

Objective: Examine interactions between perinatal risk factors for congenital iron deficiency (ID) using two cohorts.

Study Design: Iron status in a composite 767-member cord blood cohort and a NICU cohort of 257 infants < 33 weeks of gestation or small for gestational age (SGA). Risks for ID were examined. Cord ferritin levels < 84 µg/L defined congenital ID. Serum ferritin < 70 µg/L defined infantile ID at one-month.

Results: 31% of the cord cohort had congenital ID; risks summative (p < 0.0015). 16% of the NICU cohort had infantile ID; risks not summative. However, 32% had ID if the ferritin threshold was 100 µg/L. Being both preterm (p < 0.0001) and SGA (p < 0.05) negatively impacted cord iron status. Maternal hypertension was a novel predictor of iron status (p = 0.023 in preterm cord; p < 0.0025 in NICU).

Conclusion: Summing risks in term and understanding compounding risks in preterm infants can improve screening and management of ID in at-risk infants.