Pregnancy problems- the harmful effects of excess iron
PHN Editorial Highlight: ‘Oxidative stress during early pregnancy and birth outcomes’
The global prevalence of anaemia and its risks, especially during pregnancy, are well known. One way to address the risk is through mandatory iron supplementation to all pregnant women during the last 2 trimesters of pregnancy regardless of their iron status. This is reasonable, as point of care measurements of the hemoglobin (Hb) status are often not practical in resource-poor settings. However, too much of a good thing could be bad. The current recommendation in India is for pregnant women to take 100 mg of iron/day. Recent studies on the possible deleterious effects of unnecessary iron supplementation raise the important question – how much iron is needed before the risk outweighs the benefit?
The findings from this paper suggest that women who were even mildly anaemic appear to have benefited from iron supplementation. However, women with a relatively high, or normal hemoglobin (Hb>12 g/dL) tended to have higher oxidative stress markers in early pregnancy, and were therefore at risk of harmful effects of too much iron. This converges with earlier findings that non-anaemic pregnant women, and who consumed their recommended dose of iron supplements (as mandated for all women in India), had babies with lower gestational age, and a higher incidence of LBW.
Given the undoubtedly great risk of mortality and morbidity associated with anaemia during pregnancy, 3 important tasks lie ahead: 1) Define the risks better, particularly for mildly anaemic women, and evaluate the risk-benefit ratio as widely as possible, so that informed decisions can be made; 2) assess alternatives that will help reduce the need for so much supplementary iron, and ways to improve compliance at lower doses or to improve the absorption of iron; and 3) from an operational viewpoint, begin to evaluate the practicality of targeted iron supplementation, that is, give it to those in need. So, even though the rationale for iron supplementation during pregnancy is valid, and a real need, this and other recent papers on the topic highlights the quandary of addressing the needs of low-resource populations with unacceptably high levels of anaemia, and the prudency of advising a universal high-dose iron supplementation during pregnancy.
The paper, ‘Oxidative stress during early pregnancy and birth outcomes’ is published in the journal Public Health Nutrition and is freely available until 30th June 2016.
Authors: Lisha Shastri, Rajkumar S Pammal, Indu Mani, Tinku Thomas and Anura V Kurpad