Taking iron during pregnancy has been recommended in the past as a preventive treatment to help promote fetal and placental growth.
Recent studies have indicated that higher levels of iron in the blood may have harmful effects on pregnant women.
New research to be published in BJOG: An International Journal of Obstetrics and Gynaecology warns women who do not suffer from anaemia to be careful about the consumption of iron supplements during pregnancy.
727 non-anaemic women took part in a study in Iran. 370 women were given a 150mg ferrous sulphate tablet everyday throughout their pregnancy while 357 women were given the same dosage of a placebo.
The women were evaluated on their pregnancy outcome during their pregnancy and until six weeks after delivery. Researchers looked out for a range of conditions and changes such as the duration of pregnancy, method of delivery and weight gain and found that some of the women who were receiving the iron supplements developed hypertension and had a higher small for gestational age (SGA) birth rate. Researchers also found that iron supplementation increases the risk of copper and zinc deficiency in women.
Professor Saedeh Ziaei, from the Department of Obstetrics and Gynaecology at Tarbiat Modarres Unversity, who led the study said “A clinical trial was performed on 727 non-anemic pregnant women with hemoglobin = 13.2 gr/dl in the early stage of the second trimester to study the relationship between iron supplementation and pregnancy outcome.”
“The SGA birth rate and the number of women with hypertension disorder were higher in the women who received iron supplementation in comparison to the control group. Because routine iron supplementation is common, and our trial suggests that administering it even may have some disadvantages in non-anemic women, the rationale of routine iron supplementation in non-anemic women needs to be re-examined.”
Professor Philip Steer, BJOG editor-in-chief said, “Anaemia in women is often associated with low birth weight and preterm births but that does not mean that women should be popping iron pills, or any vitamin pills indiscriminately, to prevent poor pregnancy outcomes. Women who are not suffering from anaemia should ensure that they receive proper advice on diet and nutrition from their doctors and midwives.”
“This study shows that iron supplements may have a harmful effect on women who do not need them in the first place.”