BackgroundLow-birth-weight infants (LBW) are at an increased risk of iron deficiency that has been associated with impaired neurodevelopment. We hypothesized that iron supplementation of LBW infants improves cognitive scores and reduces behavioral problems until school age.MethodsWe randomized 285 marginally LBW (2,000-2,500 g) infants to receive 0, 1, or 2 mg/kg/day of iron supplements from 6 weeks to 6 months of age. At 7 years of age, 205 participants were assessed regarding cognition using Wechsler Intelligence Scale for Children (WISC-IV) and behavior using the parental questionnaires Child Behavior Checklist (CBCL) and Five to Fifteen (FTF).ResultsThere were no significant differences between the intervention groups in WISC-IV or FTF. However, the CBCL scores for externalizing problems were significantly different, in favor of supplemented children (P=0.045). When combining the supplemented groups, they had significantly lower scores for externalizing behavior compared with placebo (median (interquartile range): 44 [34;51] vs. 48.5 [41;56] P=0.013), and their risk ratio (95% confidence interval) for a total behavioral score above the cutoff for clinical problems was 0.31 (0.09-1.0), P=0.054.ConclusionLower scores of externalizing behavior in supplemented children support our previous findings at 3 years, and suggest that iron supplementation may have long-lasting effects on behavioral functions.

Introduction Low birth weight (LBW, <2500 g) may predict an increased risk of an adverse cardiometabolic profile later in life, but long-term effects in different populations and birth weight strata are still unclear. We explored laboratory markers of cardiometabolic risk in children born with marginally LBW (2000–2500 g). Methods This was a prospective longitudinal cohort study including 285 Swedish marginally LBW children and 95 normal birth weight (NBW, 2501–4500 g) controls. At 3.5 and 7 years of age, blood samples for glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), cholesterol, triglycerides, high- and low density lipoprotein (HDL and LDL), apolipoprotein B (ApoB) and apolipoprotein A1 (ApoA1) were assessed and compared between the groups. Results No significant differences in levels of insulin, HOMA-IR, hs-CRP or blood lipids were observed between marginally LBW and NBW children. At 7 years there was a higher proportion of marginally LBW children with elevated levels of insulin, defined as above the 90 th percentile of the control group (21% vs 8.6%, p = 0.038). This association was, however, confounded by maternal ethnicity. In marginally LBW children born small for gestational age (SGA), mean fasting glucose was significantly higher compared to controls (4.7 vs 4.5 mmol/L, p = 0.020). Conclusions There were no significant differences in insulin, insulin resistance, hs-CRP or blood lipids between the marginally LBW children and controls. The subgroup of marginally LBW children born SGA may present early signs of glucose imbalance already at school age.

BackgroundBeing born with very low birth weight (<1500 g) is associated with poorer neurocognition later in life. The aim of this study was to explore neurodevelopmental functions in those born with marginally LBW (2000-2500 g).MethodsThis was originally a randomized controlled trial investigating the effects of early iron supplementation in 285 marginally LBW children. Herein, we explored the combined marginally LBW group and compared their results to 95 normal birth weight (NBW; 2501-4500 g) controls in an observational design. At 7 years, a pediatric psychologist tested the children using Wechsler Intelligence Scale for Children (WISC IV), Beery-Buktenica developmental test of Visual-Motor Integration (Beery VMI), and Test of Everyday Attention for Children (TEA-Ch).ResultsThe marginally LBW children had lower verbal comprehension intelligence quotient (IQ) (104 vs. 107, P=0.004), lower VMI scores (96.5 vs. 100, P=0.028), and lower total mean TEA-Ch scores (8.5 vs. 9.7, P=0.006), compared to controls. Also, the marginally LBW children group had a higher proportion of children below -1 SD for VMI and TEA-Ch.ConclusionsMarginally LBW children had lower verbal comprehension IQ, lower visual-motor integration, and lower attention performance than NBW children, suggesting an increased risk of cognitive difficulties in early school age.