What you should know about anemia during pregnancy

During pregnancy, your body’s need for nutrients like iron, folate, and vitamin B12 increases significantly, and it can be difficult to keep up. When those needs aren’t met, you can develop a mild case of anemia in pregnancy, which is fairly common among pregnant people. In some cases, though, anemia in pregnancy can become severe and put your developing baby at risk. 

That’s why physicians recommend pregnant individuals get tested for anemia in pregnancy and diligently treat any signs of the condition. Here, we’ll cover everything you need to know about anemia in pregnancy, including causes, risk factors, symptoms, treatment, and prevention.

What is anemia? 

Anemia occurs when you have a hemoglobin deficiency, according to the American College of Obstetricians and Gynecologists (ACOG). Hemoglobin is a protein in your red blood cells responsible for delivering oxygen throughout your body. When your hemoglobin is low, your organs and tissues receive less oxygen, which can lead to symptoms like dizziness and exhaustion and health complications like heart issues and developmental delays in infants and children.  

Approximately 3 million Americans have anemia. There are several types of anemia; the most common of which is iron deficiency anemia. Anemia can range from mild to severe, depending on the type, but it’s a particular concern during pregnancy because it can put the pregnancy at risk of  preterm birth, low birth weight, and developmental delays. 

But anemia in pregnancy doesn’t only affect the fetus; it can also increase your own risk of cardiac issues and immune system dysfunction and cause potential issues after your baby is born because of the blood loss during childbirth. 

“Birth is normally an event that occurs with a large amount of blood loss, so along with the greater requirements for oxygen in the blood to make the baby, the person’s body needs to be able to withstand a great amount of blood loss at the time of the birth,” says P. Fadwah Halaby, CNM, a certified nurse midwife and founder of Midwife360. “The higher [your] hemoglobin and hematocrit are during pregnancy, the lesser the effects of the blood loss at birth.”

Who is at risk for anemia during pregnancy? 

Simply being pregnant can cause an increased risk of anemia. In fact, anemia is one of the most common conditions affecting pregnant people, according to the CDC—though it’s worth noting, that a study published in the International Journal of Gynecology & Obstetrics found a significant difference in how the CDC and the World Health Organization (WHO) measure anemia in pregnancy, resulting in vastly different reported rates (10.9% according to the former agency and 22.9% according to the latter). That said, the study noted, “anemia during pregnancy remains an important public health issue,” even if the “magnitude may be overestimated.” 

You can develop anemia at any point during your pregnancy, but “the most common trimester for anemia-related issues is usually the third trimester,” says Michael Green, MD, a board-certified OB-GYN in Lake Arrowhead, California. This is because blood volume steadily increases throughout your pregnancy, reaching a peak in the third trimester. “As a result, the demand for iron, vitamin B12, and folic acid (essential nutrients for healthy red blood cell production) increases, making pregnant individuals more susceptible to anemia during this time,” Dr. Green says.

While anyone can become anemic during their pregnancy, certain people are at higher risk than others, according to the American Society of Hematology. These include:

• People carrying more than one fetus
• People with low-iron diets
• People who had a heavy menstrual flow before pregnancy
• People whose pregnancies were closely spaced
• People with severe morning sickness and vomiting

While anemia during pregnancy is common, Halaby says most people who experience it can still go on to have healthy pregnancies. “You can have anemia and also have a successful pregnancy and birth,” she says. “However, you may not feel very energetic, and you would be at risk for the negative effects of blood loss at birth sooner than someone who is not anemic.” 

Causes of anemia in pregnancy

Anemia is more likely to develop in pregnancy because of the increased demands put on your body during this time—particularly the 20% to 30% increase in blood volume. This is known as physiological anemia of pregnancy. “During pregnancy, the body produces more blood to bring oxygen to the mother and fetus,” Dr. Green says. “In the case of anemia, one may not get the required oxygenation and other nutrients necessary to develop or stay healthy.” Basically, the more blood you have flowing through your body, the more nutrients you need.

There are several types of pregnancy-related anemia, Dr. Green says, including physiological anemia,  low iron levels (iron deficiency anemia) or a vitamin B-12 deficiency (cobalamin deficiency). “[Iron or B12 deficiencies are] almost always caused by some type of nutritional imbalance of a necessary vitamin or mineral,” he says. In rare cases, anemia in pregnancy may be caused by a genetic influence or component, Dr. Green adds.

Here, we’ll look at the three most common types of deficiency anemias in pregnancy. In determining the type of anemia, it is important your provider order specialized blood tests to check for specific deficiencies.

Iron deficiency anemia

Iron deficiency is, by far, the most common cause of anemia in pregnancy. Getting enough iron is crucial for producing hemoglobin and delivering oxygen to the fetus; while mild iron deficiency anemia can cause symptoms like fatigue, weakness, and shortness of breath, severe cases may lead to premature birth, low birth weight, and postpartum depression, according to the Mayo Clinic. Most cases of iron deficiency anemia are caused by reduced consumption of iron-rich food, such as red meat,  green leafy vegetables, or iron-fortified bread and cereal. Iron deficiency anemia may also occur as a result of heavy or frequent menstrual bleeding (before becoming pregnant) or bleeding during pregnancy.

Folate deficiency anemia

Folate is another nutrient that’s necessary for producing new blood cells, and a deficiency during pregnancy can increase the risk of a neural tube defect, also known as spina bifida. The good news is taking a prenatal vitamin containing the appropriate amount of folate can prevent about 50% of neural tube defects, according to the American Academy of Pediatricians. The CDC recommends all pregnant women consume 400 micrograms (mcg) of folate each day, through a combination of folate-rich foods and folic acid supplementation with prenatal vitamins. Foods like breads, cereals, pastas, rice, and other grain products are enriched with extra folate.

Vitamin B12 deficiency

A vitamin B12 deficiency during pregnancy is fairly rare, but it can affect vegetarians and vegans because B12 is only found in animal-based foods and nutritional yeast. During pregnancy, B12 plays an important role in placenta growth and function and fetal growth. Prenatal vitamins typically contain B12;  if you eat a plant-based diet or have a history of B12 deficiency, you can talk to your healthcare provider about potential additional supplementation.

Symptoms of anemia in pregnancy

Most cases of anemia during pregnancy develop progressively, with symptoms showing up in the later months of your pregnancy as your iron and other nutrient stores become depleted. Symptoms of anemia in pregnancy include:

• Unusual levels of exhaustion or fatigue
• Feeling weak or depleted
• Unusually pale skin
• Racing heartbeat
• Shortness of breath
• Difficulty focusing or concentrating
• Dizziness or feeling like you are going to pass out

That said, these symptoms don’t definitively mean you have anemia; many can also signal other conditions or simply represent fatigue typical during pregnancy. The only way to know for sure that you have anemia during pregnancy is via a blood test. The ACOG suggests you get screened for anemia in your first trimester and then again between weeks 24 and 28. 

How to treat anemia in pregnancy

Anemia during pregnancy is treatable, but how it’s treated depends on the type of anemia you have, how severe it is, any additional underlying conditions, and how your pregnancy is progressing.

In many mild cases, you can treat pregnancy-related anemia naturally with dietary changes and an over-the-counter prenatal vitamin or other nutritional supplement, but it’s possible you’ll need more than that. “In severe cases, a doctor may even prescribe you an iron supplement,” says Dr. Greene, adding that in the worst cases, a blood transfusion might be called for. A 2020 study found that intravenous iron infusions may help as well.

According to the U.S. Office on Women’s Health, pregnant people need about 27 milligrams of iron a day (potentially more if you’re vegetarian or vegan), 600 micrograms of folate, and 2.6 micrograms of Vitamin B12. If you’re looking to incorporate more sources of iron to treat iron deficiency anemia, try the following:

• Iron-enriched cereal and bread
• Beef liver
• White beans
• Spinach
• Lentils
• Tofu
• Chickpeas
• Beef
• Chicken
• Eggs
• Cashews
• Broccoli

If you are looking to treat anemia quickly, Halaby suggests supplements containing beef liver or liquid iron supplements made with chlorophyll and vitamin C, which are also typically less constipating than other iron supplements. Keep in mind that dairy impairs the absorption of iron; if you consume an excess of dairy, you can become iron deficient—so if you’re taking an iron supplement, it’s important that you don’t take it with any dairy.

Preventing anemia during pregnancy

It’s possible to prevent anemia in pregnancy, typically by sticking to an iron-rich diet. “Consuming iron and nutrient-rich foods is still the best preventive treatment for anemia,” Dr. Green says. If you’re planning or trying to get pregnant—especially if you have a history of anemia—start loading up on those nutrients now. Just be sure not to exceed the FDA recommended daily amount, as it’s possible to have iron overload, which can significantly impact your health. Dr. Green says people who are anemic before pregnancy have a higher risk of developing severe anemia during pregnancy.

The ACOG recommends you start taking a prenatal vitamin with iron and folic acid as soon as you begin trying to conceive.

If you have any further questions about anemia in pregnancy, including how to treat and prevent it, don’t hesitate to reach out to your healthcare provider.