Written by Jessica Patella, ND. This study demonstrates that iron deficiency during pregnancy increases the risk of having premature babies and babies with low birth weights and anemia.
According to the World Health Organization, iron deficiency is the most common nutrient deficiency in the world. In addition to contributing to general poor health and premature death (1, 2) iron deficiency may cause anemia, which affects almost 50% of pregnant women worldwide (1, 3). Maternal iron deficiency has been linked to a higher risk of having a premature infant with low birth weight and anemia (1, 4).
A recent study in England found that depleted iron stores early in pregnancy are associated with a higher risk of having a low birth weight infant (1). This is a concern because infants with low birth weight have a greater risk of dying, as well as cognitive dysfunction and cardiovascular disease later in life (1, 5).
Iron deficiency can be present with or without anemia. Anemia is the final stage of iron deficiency when the cells have been exhausted of iron stores (1). The most common way to measure iron deficiency is with hemoglobin levels. Although because blood volume increases with pregnancy, hemoglobin levels may not be completely accurate (110 g/l that otherwise would be considered within the normal range, indicates anemia at 20 weeks gestation). Another way to measure iron levels is with biomarker sF (serum ferritin), which indicates how much iron is stored in the body (levels under 15 micrograms/l typically indicate depleted stores in women) (1).
A total of 362 women were included in the research study, with an average age of 31+/- 6 years. Maternal blood was measured for iron status in the first trimester of pregnancy and infants’ birth weights were recored at time of birth. The following results were observed:
- Overall, 18% of babies were born weighing less than the 10th percentile in weight.
- 23% of mothers were depleted in iron (sF <15 micrograms/l).
- 14% were anemic after 20 weeks of gestation (hemoglobin <105 g/l).
- Maternal anemia in the first trimester was associated with a reduction in 15 percentile points in infant birth weight (95%CI 1, 29; P=0.04).
- Maternal iron depletion in the first trimester (sF<15 micrograms/l) was associated with a higher risk of having a low birth weight infant (OR 2.2, 95%CI 1.1, 4.1; P=0.02).
- For every 10 g/l increase in maternal hemoglobin levels in the first trimester the risk of low infant birth weight was reduced by 30% (95%CI 0,40; P=0.03).
- For every 10 g/l increase in maternal hemoglobin levels in the first trimester there was an increase in gestation age by 2 days (95% CI 0.2, 3.0; P=0.03).In conclusion, anemia and iron depletion in the first trimester of pregnancy are associated with a higher risk of having a baby with a low birth weight (1). Researchers suggest this may be due to the fact that a mother with depleted iron stores may not be able to deliver enough oxygen through the placenta, resulting in low birth weight in the infant (1). Currently, routine supplementation of iron is notrecommended in pregnancy. The researchers suggest screening for iron depletion (biomarker sF) in the early stage of pregnancy, and if the levels are low, supplementing with iron and giving nutritional advice to increase iron stores in the body (1).
Source: Alwan, Nisreen A., et al. “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 113.12 (2015): 1985-1992.
© The Authors 2015. Creative Commons Attribution licence (http://creativecommons.org/licenses/by/3.0/)
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Posted June 8, 2015.
Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health. She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians. Visit her website at www.awarenesswellness.com.
References:
- Alwan NA, et al. Maternal iron status in early pregnancy and birth outcomes:insights from the Baby’s Vascular health and Iron in Pregnancy study. 2015 British Journal of Nutrition. DOI:10.1017/S0007114515001166
- WHO (2010) Micronutrient deficiencies.
- UNICEF/UNU/WHO (2001) Iron Deficiency Anemia: Assessment, Prevention, and Control. Geneva: World Health Organization.
- Lone F, Qureshi R & Emanuel F (2004) Maternal anaemia and its impact on perinatal outcome. Trop Med Int Health 9, 486–490.
- Bhutta AT, et al. (2002) Cognitive and behavioral outcomes of school-aged children who were born preterm: a meta-analysis. JAMA 288, 728–737.
