Iron status at birth and at 4 weeks in term small-for-gestation infants in comparison with appropriate-for-gestation infants.

Objective: To determine body iron stores at birth in term small-for-gestational age (SGA) infants as compared to appropriate-for-gestational age (AGA) infants.

Methods: In this prospective study, mother-infant pairs with gestation of  ≥ 37 weeks and birth weight of at least 1.5 kg were enrolled. Asymmetric SGA infants were taken as cases and term AGA infants as controls. Maternal, cord blood, and infant blood samples at 4 weeks were obtained for measurement of various iron indices - cord serum ferritin, serum ferritin at 4 weeks, and correlation among maternal and neonatal iron indices - Hb, serum iron, ferritin, and total iron binding capacity (TIBC).

Results: There were 50 SGA and 50 AGA mother-infant pairs. Cord serum ferritin levels were low in SGA group as compared to AGA [median (IQR): 68 (30,136) vs. 141 (63,259), p = 0.007]. The proportion of infants with 'low' cord ferritin (< 40 μg/l) were more in SGA [p = 0.05]. There was no correlation among various maternal and neonatal cord iron parameters. The serum ferritin levels at 4 weeks were similar in both the groups (p = 0.16).

Conclusions: Term SGA infants have lesser total iron stores as compared to AGA infants at birth. Future studies can be designed to look at long-term neurodevelopmental outcome of the SGA babies with low as well as normal ferritin and also the role of early iron supplementation in term SGA neonates.