Depleted maternal iron status early in pregnancy is associated with a higher risk of low birth weight babies

Depleted maternal iron status early in pregnancy is associated with a higher risk of low birth weight babies

June 3, 2015
Weekly Essentials of Health by Usana Health Sciences 
Depleted maternal iron status early in pregnancy is associated with a higher risk of low birth weight babies

At a Glance

A recent study published in British Journal of Nutrition shows that poor iron status early in pregnancy significantly increases the risk of babies born small for gestational age (SGA). 

Read more about this research below. 

Iron deficiency anemia during early pregnancy has long been linked to low birth-weight, preterm birth, and other health problems. But previous research and advice has been based on hemoglobin (Hb) levels (screening for outright deficiencies or anemia), not on other specific measures of iron deficiency.

In a new study published in the British Journal of Nutrition, researchers examined the association between maternal iron status during the first trimester of pregnancy with birth size and preterm birth by using more specific measures of iron deficiency such as serum ferritin, transferrin receptor and their ratio.  

Three-hundred sixty-two infants and their mothers were recruited for this study. Biomarkers and iron measurements were analyzed from maternal blood serum samples that had been taken during the first trimester of pregnancy.

Iron depletion during the first trimester was linked to a higher incidence of SGA. The association was even stronger when Hb measurements were included in the assessment. Although there was no evidence of a link between iron insufficiency and preterm birth, for every 10 g/l increase in the mother’s Hb level during the first half of pregnancy there was a 30% lower risk of SGA. Hb levels below 110 g/l were associated with a 300% increase in SGA risk. Contrary to other research, Hb levels in the second half of pregnancy were not associated with SGA risk.

The results of the present study indicate that depleted iron stores in early pregnancy are associated with higher risk of SGA. In some countries iron supplementation is not recommended during pregnancy except in the case of anemia. Based on the results of this study, researchers suggest that all women should be screened for iron deficiency early in pregnancy using more specific measurements, and should be offered more personal and helpful advice on improving iron status through diet and supplements.  

Nisreen A. Alwan, Janet E. Cade, Harry J. McArdle, Darren C. Greenwood, Helen E. Hayes and Nigel A. B. Simpson. Maternal iron status in early pregnancy and birth outcomes: insights from the Baby's Vascular health and Iron in Pregnancy study. British Journal of Nutrition, available on CJO2015. doi:10.1017/S0007114515001166.

Vitamin E status in women and the risk of miscarriage in early pregnancy

Vitamin E status in women and the risk of miscarriage in early pregnancy 

At a Glance A new study has found that maternal vitamin E status during the first trimester of pregnancy may influence the risk of early miscarriage in women. Read more about this research below.

Tocopherols are a family of vitamin E compounds found naturally in vegetable oils, nuts, fish, and leafy green vegetables. The nutritional benefits of vitamin E and its importance in the human diet have been well documented. However the diets of many Americans provide less than the recommended amounts of vitamin E. Low fat diets, GI tract disorders, and certain medications can further impact the availability and absorption of vitamin E.

Originally tocopherols were discovered for their role in animal reproduction, but little to date has been known about the contribution of vitamin E deficiencies in human pregnancy loss. A new study published in the American Journal of Clinical Nutrition has shown that maternal vitamin E status in the first trimester may influence the risk of early pregnancy loss. This is believed to be the first population study of early pregnancy vitamin E nutritional status and the risk of miscarriage in a human population.

The study was conducted in rural Bangladesh, a typically undernourished population. The researchers measured alpha-tocopherol and gamma-tocopherol plasma status of a case-cohort study of 1,605 pregnant Bangladeshi women. 1,161 of the women (72.3%) had low-to-deficient vitamin E status defined by a plasma alpha-tocopherol concentration of <12.0 µmol/L. The most important finding was that women with low alpha-tocopherol concentrations were almost twice more likely to miscarry than women with normal status. Women with low gamma-tocopherol status were also significantly more likely to miscarry than those with higher concentrations.

The cutoff of plasma alpha-tocopherol concentration 12.0 µmol/L was proposed to define vitamin E deficiency in normal, healthy adults. However, it should be noted that currently there is no clearly defined consensus on the definition of vitamin E deficiency in pregnant women because alpha-tocopherol concentrations increase with blood lipids over the course of pregnancy.

While these findings show an association between adequate alpha-tocopherol status and reduced risk of miscarriage in human populations, future studies exploring the potential beneficial effects of adequate vitamin E status during pregnancy are warranted.

Ahmed Shamim A, Schulze K, Merrill RD, et al. First trimester plasma tocopherols are associated with risk of miscarriage in rural Bangladesh. Am J Clin Nutr February 2015 ajcn.094920; First published online November 26, 2014. doi:10.3945/ajcn.114.094920