Iron in Pregnancy – How Do We Secure an Appropriate Iron Status in the Mother and Child?

Abstract

Iron deficiency and iron deficiency anemia (IDA) during pregnancy are risk factors for preterm delivery, prematurity, and small for gestational age birth weight. Iron deficiency has a negative effect on intelligence and behavioral development in the infant. It is essential to prevent iron deficiency in the fetus by preventing iron deficiency in the pregnant woman. The requirements for absorbed iron increase during pregnancy from ∼1.0 mg/day in the first trimester to 7.5 mg/day in the third trimester. More than 90% of Scandinavian women of reproductive age have a dietary iron intake below the recommended 15 mg/day. Among nonpregnant women of reproductive age, ∼40% have plasma ferritin ≤30 µg/l, i.e. an unfavorable iron status with respect to pregnancy. An adequate iron status during pregnancy implies body iron reserves ≧500 mg at conception, but only 15–20% of women have iron reserves of such a magnitude. Iron supplements during pregnancy reduce the prevalence of IDA. In Europe, IDA can be prevented by a general low-dose iron prophylaxis of 30–40 mg ferrous iron taken between meals from early pregnancy to delivery. In affluent societies, individual iron prophylaxis tailored by the ferritin concentration should be preferred to general prophylaxis. Suggested guidelines are: ferritin >70 µg/l, no iron supplements; ferritin 31–70 µg/l, 30–40 mg ferrous iron per day, and ferritin ≤30 µg/l, 60–80 mg ferrous iron per day. In women with ferritin <15 µg/l, i.e. depleted iron reserves and possible IDA, therapeutic doses of 100 mg ferrous iron per day should be advised.

Supplementation during pregnancy: beliefs and science

“…Consequently, iron supplementation is indicated unless iron stores of about 500 mg are present at the beginning of pregnancy (achieved by approximately 15-20% of women in Western countries). In Europe, the majority of women of reproductive age have a low iron status with a median plasma ferritin of &40 mg/ L, corresponding to mobilizable body iron reserves of 200-300 mg [58]. In Western countries, preconceptional or early 1st trimester plasma ferritin should indicate the need for supplementation (general prevention of IDA, or IDA treatment with a specific regimen).…”

Iron supplement use in pregnancy – Are the right women taking the right amount?

“…8,9 Other developed countries, such as the United Kingdom, Germany, Norway, New Zealand, and Australia recommend selective iron supplementation; however few of these countries provide guidance on the dose of supplemental iron. 10 The UK recommends 65 mg of elemental iron daily for non-anaemic women at increased risk of iron depletion (i.e. women with previous anaemia, multiple pregnancy, consecutive pregnancies with less than a year's interval between, and vegetarians).…”

Effect of iron supplementation during lactation on maternal iron status and oxidative stress: A randomized controlled trial

“…Much of the additional iron required is used to increase the mother's red cell mass. After giving birth, the red cells are broken down and the Hb iron contained within them is available for use or storage (Milman 2011).…”

“…The Recommended Dietary Allowance (RDA) for iron is 27 mg/d during pregnancy and 18 mg/d for non-pregnant, non-lactating women (Trumbo et al 2001). By contrast, the RDA for iron in lactation is only 9 mg/d because of the expectation that there will be no menstrual losses during the first 6 mo postpartum, and the iron accumulated during prenatal formation of maternal red blood cells can be recycled and used by the mother postpartum (Milman 2011). As a result, universal iron supplementation is generally not necessary for healthy lactating women.…”