Anemia in Pregnancy

Medically Reviewed by Traci C. Johnson, MD on August 12, 2022
5 min read

When you're pregnant, you may develop anemia. When you have anemia, your blood doesn't have enough healthy red blood cells to carry oxygen to your tissues and to your baby.

During pregnancy, your body produces more blood to support the growth of your baby. If you're not getting enough iron or certain other nutrients, your body might not be able to produce the amount of red blood cells it needs to make this additional blood.

It's normal to have mild anemia when you are pregnant. But you may have more severe anemia from low iron or vitamin levels or from other reasons.

Anemia can leave you feeling tired and weak. If it is severe but goes untreated, it can increase your risk of serious complications like preterm delivery.

Here's what you need to know about the causes, symptoms, and treatment of anemia during pregnancy.

Several types of anemia can develop during pregnancy. These include:

Here's why these types of anemia may develop:

Iron-deficiency anemia. This type of anemia occurs when the body doesn't have enough iron to produce adequate amounts of hemoglobin. That's a protein in red blood cells. It carries oxygen from the lungs to the rest of the body.

In iron-deficiency anemia, the blood cannot carry enough oxygen to tissues throughout the body.

Iron deficiency is the most common cause of anemia in pregnancy.

Folate-deficiency anemia. Folate is the vitamin found naturally in certain foods like green leafy vegetables A type of B vitamin, the body needs folate to produce new cells, including healthy red blood cells.

During pregnancy, women need extra folate. But sometimes they don't get enough from their diet. When that happens, the body can't make enough normal red blood cells to transport oxygen to tissues throughout the body. Man made supplements of folate are called folic acid.

Folate deficiency can directly contribute to certain types of birth defects, such as neural tube abnormalities (spina bifida) and low birth weight.

Vitamin B12 deficiency. The body needs vitamin B12 to form healthy red blood cells. When a pregnant woman doesn't get enough vitamin B12 from their diet, their body can't produce enough healthy red blood cells. Women who don't eat meat, poultry, dairy products, and eggs have a greater risk of developing vitamin B12 deficiency, which may contribute to birth defects, such as neural tube abnormalities, and could lead to preterm labor.

Blood loss during and after delivery can also cause anemia.

All pregnant women are at risk for becoming anemic. That's because they need more iron and folic acid than usual. But the risk is higher if you:

  • Are pregnant with multiples (more than one child)
  • Have had two pregnancies close together
  • Vomit a lot because of morning sickness
  • Are a pregnant teenager
  • Don't eat enough foods that are rich in iron
  • Had anemia before you became pregnant

The most common symptoms of anemia during pregnancy are:

  • Pale skin, lips, and nails
  • Feeling tired or weak
  • Dizziness
  • Shortness of breath
  • Rapid heartbeat
  • Trouble concentrating

In the early stages of anemia, you may not have obvious symptoms. And many of the symptoms are ones that you might have while pregnant even if you're not anemic. So be sure to get routine blood tests to check for anemia at your prenatal appointments.

Severe or untreated iron-deficiency anemia during pregnancy can increase your risk of having:

  • A preterm or low-birth-weight baby
  • A blood transfusion (if you lose a significant amount of blood during delivery)
  • Postpartum depression
  • A baby with anemia
  • A child with developmental delays

 

Untreated folate deficiency can increase your risk of having a:

  • Preterm or low-birth-weight baby
  • Baby with a serious birth defect of the spine or brain (neural tube defects)

Untreated vitamin B12 deficiency can also raise your risk of having a baby with neural tube defects.

During your first prenatal appointment, you'll get a blood test so your doctor can check whether you have anemia. Blood tests typically include:

  • Hemoglobin test. It measures the amount of hemoglobin -- an iron-rich protein in red blood cells that carries oxygen from the lungs to tissues in the body.
  • Hematocrit test. It measures the percentage of red blood cells in a sample of blood.

If you have lower than normal levels of hemoglobin or hematocrit, you may have iron-deficiency anemia. Your doctor may check other blood tests to determine if you have iron deficiency or another cause for your anemia.

Even if you don't have anemia at the beginning of your pregnancy, your doctor will most likely recommend that you get another blood test to check for anemia in your second or third trimester.

If you are anemic during your pregnancy, you may need to start taking an iron supplement and/or folic acid supplement in addition to your prenatal vitamins. Your doctor may also suggest that you add more foods that are high in iron and folic acid to your diet.

In addition, you'll be asked to return for another blood test after a specific period of time so your doctor can check that your hemoglobin and hematocrit levels are improving.

To treat vitamin B12 deficiency, your doctor may recommend that you take a vitamin B12 supplement.

The doctor may also recommend that you include more animal foods in your diet, such as:

  • meat
  • eggs
  • dairy products

Your OB may refer you to a hematologist, a doctor who specializes in anemia/ blood issues. The specialist may see you throughout the pregnancy and help your OB manage the anemia.

To prevent anemia during pregnancy, make sure you get enough iron. Eat well-balanced meals and add more foods that are high in iron to your diet.

Aim for at least three servings a day of iron-rich foods, such as:

  • lean red meat, poultry, and fish
  • leafy, dark green vegetables (such as spinach, broccoli, and kale)
  • iron-enriched cereals and grains
  • beans, lentils, and tofu
  • nuts and seeds
  • eggs

Foods that are high in vitamin C can help your body absorb more iron. These include:

  • citrus fruits and juices
  • strawberries
  • kiwis
  • tomatoes
  • bell peppers

Try eating those foods at the same time that you eat iron-rich foods. For example, you could drink a glass of orange juice and eat an iron-fortified cereal for breakfast.

Also, choose foods that are high in folate to help prevent folate deficiency. These include:

  • leafy green vegetables
  • citrus fruits and juices
  • dried beans
  • breads and cereals fortified with folic acid

Follow your doctor's instructions for taking a prenatal vitamin that contains a sufficient amount of iron and folic acid.

Vegetarians and vegans should talk with their doctor about whether they should take a vitamin B12 supplement when they're pregnant and breastfeeding.