The benefits of intermittent oral iron supplementation plus folic acid are similar to those of daily supplementation in terms of maternal and infant outcomes, according to the results of a recent systematic analysis.1
Daily iron supplementation throughout pregnancy has been the traditional treatment of gestational anemia. However, poor adherence because of adverse effects, supply interruptions, and safety concerns has limited the use of this practice. To help reduce the adverse effects associated with daily iron supplementation, which include constipation and nausea, and to increase ease of use of the regimen, intermittent supplementation of iron—1 to 3 times per week on nonconsecutive days—has been proposed. In this new review study, researchers evaluated the benefits and harms of intermittent oral iron supplementation alone or with folic acid or other vitamins and minerals on neonatal and pregnancy outcomes.
The researchers used data from 18 trials that included a total of 4072 women. All of the included trials compared daily iron supplementation with intermittent iron supplementation. Three studies included data for iron supplementation alone, 12 studies included data on iron plus folic acid, and 3 studies focused on iron plus vitamins and minerals.
Analysis of the available data revealed no clear differences between trial groups for neonatal primary outcomes, including mean infant birthweight and rates of low birthweight and premature birth. Neonatal deaths and congenital anomalies were not reported in any of the studies. In addition, there was no clear evidence of any differences in the rates of maternal anemia at term.
Compared with daily supplementation, intermittent supplementation was associated with fewer adverse effects and a lower risk of having a high hemoglobin concentration (more than 130 g/L) in the second or third trimester. Among women receiving any type (daily or intermittent) of supplementation with iron plus folic acid, no differences in the rates of iron-deficiency anemia were found.
Overall, the evidence for use of intermittent iron supplementation is limited and the quality of what little evidence exists is poor. However, this new review provides the most comprehensive summary of the evidence evaluating the benefits and harms of intermittent iron supplementation to date, according to the study authors. Considering the available evidence, the study authors conclude that intermittent iron supplementation may be a feasible alternative to daily iron supplementation among pregnant women who are not otherwise anemic and who have adequate medical care.
- Intermittent iron supplementation, compared with daily supplementation, may decrease the likelihood of high hemoglobin concentrations occurring in mid and late pregnancy, which potentially decreases the risk of premature birth and having a small-for-gestational-age neonate.
1. Pena-Rosas JP, De-Regil LM, Dowswell T, Viteri FE. Intermittent oral iron supplementation during pregnancy. Cochrane Database Syst Rev. 2012;7:CD009997.