Should you measure maternal iron before prescribing supplements

Pregnant women who are supplementing with high doses of iron without considering their dietary intake may be at risk of reduced foetal growth in the second trimester, according to new research published online in Nutrition Journal.[1] Researchers in South Korea investigated whether there was a connection between total iron intake (diet and supplements) and foetal growth at mid-pregnancy, measuring iron intake from food and supplements in 377 women who were 12-28 weeks gestation. They reported a significant, measurable retardation of growth of the foetus in mothers in the highest tertile of the study, about 90% of who were taking supplemental iron. Supplement users had three times higher than recommended daily intake (RDI) average iron intake and the source was mainly from supplements. “Foetal biometry and growth were not different according to the dietary iron intake adjusting for iron supplementation use, but were greater in the babies of mothers with iron supplementation than the babies of mothers without iron supplementation adjusting for dietary iron intake,” wrote Hwang et al. “These results indicate that supplemental iron in pregnancy is needed for foetal growth but also indicate that excessive consumption of iron, mainly from the supplements at mid-pregnancy, may have adverse effects on foetal growth at mid-pregnancy.”