Iron deficiency in pregnancy: effects on the newborn

Iron deficiency during pregnancy affects a significant portion of women in countries with low economic wealth and is not uncommon in pregnant women in industrialized countries. Inadequate intake of iron related to diets poor in bioavailable iron is often responsible for iron deficiency before pregnancy, and metabolic adjustments (such as mobilization of iron stores and increased absorption) are insufficient to meet increasing needs during pregnancy. The effects of iron deficiency on the fetus are still controversial. Numerous measures, including the evaluation of erythrocyte ferritin, favor the hypothesis that the level of iron stores in newborns is related to maternal iron status and that the materno-fetal unit is dependent on exogenous iron, which is necessary to prevent iron deficiency in both mothers and infants. In industrialized countries, iron supplements should be prescribed for pregnant women in the third trimester, when the need for iron is prominent. In developing countries, supplementation should be initiated as soon as possible after conception because of the high prevalence of iron deficiency at the onset of pregnancy. The results of studies comparing intermittent with daily supplementation remain controversial.