Serum Ferritin – The Role of Birthweight: A Comparative Study

Aims: To determine the serum ferritin levels amongst low birth weight neonates and to correlate it with different categories of low birth weight. To determine the role of birth weight in predicting changes in serum ferritin levels.

Methodology: This was a prospective comparative cross sectional study which was carried out at the Neonatal Intensive Care Unit of the University of Nigeria Teaching Hospital (UNTH), Enugu, Nigeria between June and December 2014. The study included 140 newborns of all birth weights delivered at the UNTH. These were categorized into extremely low birth weight (ELBW), very low birth weight (VLBW), low birth weight (LBW) normal birth weight and macrosomic. Babies with C-reactive protein levels > 10mg/dl, who were intra-uterine growth restricted, and whose mothers had conditions associated with low iron stores were excluded from the study. Anthropometric measurements were done for all subjects. Serum ferritin was measured at birth and this was correlated with birth weight and gestational age.

Results: Serum ferritin levels ranged from 20.6 to 296.4µg/l. Ferritin levels showed a steady increase in relation to birth weight. (F = 42.453, P < .001). There was a significant association between ferritin levels and categories of birth weight. ELBW babies were 98 times more likely to have low ferritin levels than babies with normal weight (P < .001, OR = 97.600, 95% C.I = 10.083 – 944.711). VLBW and LBW babies were more likely to have low ferritin levels than babies with normal weight (P < .001, OR = 0.070, 95% C.I = 0.017 – 0.291)(P = .006, OR = 0.201, 95% C.I = 0.064 – 0.635). Only birthweight was a significant positive predictor of low ferritin levels (P = .024).

Conclusion: Serum ferritin in new-borns showed a significant association with birth weight. Birth weight is a positive predictor of low serum ferritin levels.