During pregnancy, the body produces more blood to support the growing fetus and supply organs. With iron deficiency anemia in pregnancy, the body does not have enough iron to meet these needs.

The body needs iron to produce a protein in red blood cells called hemoglobin that carries oxygen from the lungs throughout the body. If a person has iron deficiency anemia, their blood cannot carry enough oxygen to tissues around the body, and they may become tired and weak.

Doctors define anemia as a low red blood cell count, low hematocrit, or low hemoglobin concentration. Doctors typically define anemia during pregnancy as a hemoglobin concentration below 11.0 grams per deciliter.

This article explores iron deficiency anemia in pregnancy, symptoms, complications, and treatment.

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Iron deficiency anemia in pregnancy can have a negative impact on both the pregnant person and the developing fetus.

Pregnant people may experience the following symptoms of iron deficiency anemia:

  • tiredness
  • weakness
  • skin that looks paler than usual
  • skin that appears yellowish
  • irregular heartbeats
  • heart palpitations
  • breathing difficulties
  • sleep problems
  • dizziness
  • fainting
  • brittle nails
  • hair loss
  • pounding in the ears
  • headaches

Iron deficiency anemia in pregnancy can cause complications for the pregnant person and the fetus.

Pregnant people may have a greater risk of:

After giving birth, a person may also experience cognitive impairment, behavioral difficulties, and problems with their milk supply.

Babies born to people with anemia have an increased risk of dying and experiencing health complications, such as:

  • spontaneous abortion
  • premature delivery
  • stillbirth
  • low birth weight (LBW)
  • small for gestational age (SGA)
  • high blood pressure
  • neurological problems

Iron deficiency anemia occurs during pregnancy because a person’s overall iron needs are significantly greater than when they are not pregnant.

A person’s need for iron increases exponentially when they are pregnant. This is because the placenta, fetus, and additional red blood cells require iron. Further, the body must compensate for iron losses during the baby’s birth.

Pregnant people require approximately 1000–1200 milligrams (mg) of iron throughout pregnancy, assuming an average weight of 55 kilograms. Almost 350 mg of this amount is for fetal and placental growth, and around 500 mg is for red blood cell mass increase.

In addition, blood loss during birth is responsible for roughly 250 mg of iron loss. If someone’s iron intake does not meet these requirements, they may develop iron deficiency anemia.

Furthermore, up to 80% of iron deficiency anemia cases occur in places where people experience chronic malnutrition and nutritional deficiencies.

Therefore, iron deficiency anemia happens most frequently in low-income countries. However, people in middle- and high-income countries may also experience iron deficiency anemia.

In developing countries, iron deficiency may also occur due to blood loss associated with gastrointestinal parasites.

Treatment for iron deficiency anemia in pregnancy may depend on a person’s symptoms and overall health. Doctors may also tailor their treatments depending on the severity of the anemia.

Oral iron supplementation

Oral iron supplementation is the first-line treatment for iron deficiency anemia. These supplements should contain 40–100 mg of elemental iron. A person usually takes iron supplements daily or several times each day. Although sustained-release iron supplements exist, the body does not absorb them well.

To maximize iron absorption, people should take their supplements on an empty stomach with a form of vitamin C, such as orange juice.

Additionally, people should take iron supplementation 1 hour before or 2 hours after consuming certain substances, including:

  • tea
  • coffee
  • milk
  • soy products
  • eggs
  • antacids
  • calcium
  • proton pump inhibitors
  • thyroxine

Doctors check the person’s response to oral iron supplementation by measuring their hemoglobin level 2–4 weeks after they begin treatment.

After hemoglobin measurements normalize, a person should continue taking iron supplementation for a minimum of 3 months and until 6 weeks after the baby’s birth.

Intravenous (IV) iron

Doctors may recommend switching oral iron supplementation to IV therapy if the person:

  • does not respond to oral iron
  • does not tolerate oral iron
  • does not take the supplement as recommended
  • is weak
  • requires rapid treatment because of bleeding or other health conditions

Previously, IV iron formulations caused potentially severe side effects such as anaphylaxis. Due to this, doctors limited their use. However, newer IV iron treatments are safer.

A person may have an increased risk of developing iron-deficiency anemia during pregnancy if they:

  • have two pregnancies without much time between them
  • have a multiple pregnancy
  • are vomiting regularly due to morning sickness
  • experienced heavy menstrual flow before pregnancy
  • have a history of anemia before becoming pregnant
  • consume a diet low in iron

The key to preventing iron deficiency anemia in pregnancy is to ensure the pregnant person consumes enough iron to meet their needs. They should eat a healthy, varied diet and complement this with iron supplements to help prevent their iron stores from becoming depleted.

Many pregnant people do not receive enough iron in their diets, even through fortified foods and dietary supplements. For example, some studies indicate that 40% of females ages 19–34 years do not consume enough iron.

Experts recommend that the total iron intake during pregnancy be at least 1000 mg.

In addition, the National Institutes of Health recommend that pregnant people consume at least 27 mg of iron each day.

Iron deficiency anemia in pregnancy occurs when a person’s iron intake fails to meet their needs. During pregnancy, a person’s iron requirements increase exponentially due to the needs of the growing fetus.

A person with iron deficiency anemia may experience weakness, tiredness, headaches, skin that looks paler than usual, and other symptoms. In addition, the fetus may also experience adverse effects.

Doctors typically treat iron deficiency anemia in pregnancy with oral iron supplementation. However, in some circumstances, they may recommend intravenous iron instead.