Preventive daily or intermittent iron or iron+folic acid supplementation taken by women during pregnancy reduces anaemia and iron deficiency in mothers. There is evidence that taking iron or iron and folic acid daily or intermittently has a similar effect in reducing anaemia at term and improving haemoglobin concentrations in the mother. Daily iron or iron and folic acid is associated with adverse side effects.
During pregnancy, women need iron and folate to meet their own needs and those of their developing fetus. There is concern that pregnant women may become deficient in these nutrients and unable to supply them in sufficient quantities to their fetus. Low iron and folate levels in women can cause anaemia, and low folate periconceptionally increases the risk of neural tube defects (NTD). Anaemia can make women tired, faint, and at increased risk for infection. Iron and folate deficiencies could impact the mother and her pregnancy, and the baby. In this review of 49 trials, involving 23,200 pregnant women, we found data to conclude that the use of iron or iron+folic acid supplements was associated with a reduced risk of anaemia and iron deficiency in pregnancy and that daily iron supplementation was associated with increased risk of haemoconcentration at term. The effects of iron or iron+folic acid on reducing anaemia and iron deficiency anaemia at term were similar whether the supplements were taken daily or weekly. More research is needed on the safe and effective amounts of iron and schemes to provide in preventive supplementation programs for pregnant women on functional outcomes, particularly in low-income countries.