Iron Supplements Safely Reduce Risk for Iron Deficiency Anemia in Marginally LBW Infants

Fran Lowry

September 08, 2010

September 8, 2010 — Iron supplements reduce the risk of developing iron deficiency anemia in marginally low birth weight (LBW) infants with no adverse effects, according to the results of a large, randomized Swedish study published online September 7 in Pediatrics.

According to the article, LBW infants (<2500 g) are at risk for early iron deficiency, which is associated with poor neurologic development. Moreover, the proportion of infants with marginally LBW (from 2000 to 2500 g) is increasing.

"The World Health Organization and the American Academy of Pediatrics recommend iron supplements for all LBW infants, without distinguishing between extremely LBW (<1000 g) and MLBW infants," write Staffan Berglund, MD, from Umeå University, Sweden, and colleagues. "However, other authorities do not recommend iron supplements for MLBW infants, and there are large variations in clinical practices with respect to indications, doses, times of initiation, and duration of iron supplement administration."

The authors add that there is a striking lack of data about possible benefits and risks of iron supplementation in MLBW infants, who represent more than 60% of all LBW infants. The aim of this study was to investigate the short-term laboratory and functional effects of such supplementation in this population.

The investigators randomly assigned 285 healthy MLBW infants to receive 1 of 3 iron supplement doses: 0 (placebo), 1, or 2 mg/kg per day from the age of 6 weeks to 6 months. At 6 months, the researchers measured hemoglobin and ferritin levels, transferrin saturation, mean cell volume, and transferrin receptor levels. The infants' growth and morbidity were monitored.

The researchers found a significant dose-dependent effect on hemoglobin and the other indicators of iron status at 6 months. The prevalence of iron deficiency was 36% in the placebo group, 8.2% in the 1 mg/kg/day group, and 3.8% in the 2 mg/kg/day group (P < .001). The prevalence rates of iron deficiency anemia were 9.9% in the placebo group, 2.7% in the 1 mg/kg/day group, and 0% in the 2 mg/kg/day group (P = .004).

Infants in the placebo group who were exclusively breast-fed had a prevalence rate of iron deficiency anemia of 18%. Growth and morbidity were similar in all groups, the authors report.

"For the first time, we have shown that MLBW infants, who represent 3% to 5% of all newborn infants in affluent countries, have a relatively high risk of developing [iron deficiency anemia], even if they are otherwise healthy and well nourished," the authors write in their conclusion. "This can be prevented effectively with iron drops at a dose of 2 mg/kg per day from 6 weeks to 6 months, a supplementation that we conclude to be safe with respect to growth and morbidity."

They add that the long-term health effects of early iron deficiency anemia and the effects of early iron supplementation in MLBW infants are not yet fully known. Because of this, they plan to continue to monitor the infants in this study up to 7 years of age.

The study was supported by the Swedish Research Council, the Västerbotten County Council, the Jerring Foundation, the Oskar Foundation, and the Medical Faculty of Umeå University. The iron drops were provided by Astra Zeneca. The study authors have disclosed no relevant financial relationships.

Pediatrics. Published online September 7, 2010.


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