Daily iron supplements not necessary during pregnancy

Pregnant women who take daily iron supplements may benefit just as much from reducing them to once a week, new research suggests.

Dr Juan Pablo Pena-Rosas of the World Health Organization in Geneva, Switzerland, and colleagues carried out a Cochrane review of the evidence to date.

They explain that a lack of iron can cause anaemia in pregnant women, potentially increasing the risk of childbirth complications and causing harm to the baby. Equally, too much iron in the blood may increase the risk of prematurity or low birthweight.

Daily iron supplements are recommended for all pregnant women in some countries, and for those with anaemia in the UK.

The review examined figures from 18 trials of a total of 4,072 pregnant women who took either preventative iron supplements alone, with folic acid, or with multi-vitamins and minerals.

Those who took iron supplements once, twice or three times a week were at no higher risk of anaemia by the end of their pregnancy than those who took them daily. Their babies were no more likely to be premature or have a low birth weight. These women were also less likely to experience side-effects such as nausea, constipation and excessively high blood iron levels.

Dr Pena-Rosas says: "Intermittent iron supplementation could be considered as a feasible alternative to daily supplementation for preventing anaemia during pregnancy, particularly in developed countries where anaemia in pregnancy is not a public health problem and there is good antenatal care for monitoring anaemia status."

But he added: "At the moment evidence is limited and the quality of the trials included in our review was generally low."

The team call for further research to clarify which iron doses during pregnancy are safest for both mother and baby.

Intermittent oral iron supplementation during pregnancy. Pena-Rosas, J. P. et al. Cochrane Database of Systematic Reviews 2012, Issue 7.doi: 10.1002/14651858.CD009997.