What do you need to know about anemia during pregnancy?
The wonder and joy of pregnancy is matched by the body's ability to adapt to looking after the growing baby. In addition to the mother's physiologic needs, there is the additional need to provide the building blocks to optimally grow baby. All this construction requires energy and oxygen as the fuel that helps drive the engine.
Oxygen in the air that we breathe is delivered to the cells of the body by hemoglobin, a protein molecule found in red blood cells. The normal ranges for hemoglobin depend on the age and, beginning in adolescence, the gender of the person. For example, the normal ranges of hemoglobins for background comparison are:
- Newborns: 17 to 22 gm/dl
- Babies 1 week of age: 15 to 20 gm/dl
- Babies 1 month of age: 11 to 15 gm/dl
- Children: 11 to 13 gm/dl
- Adult men: 14 to 18 gm/dl
- Adult women: 12 to 16 gm/dl
- Men after middle age: 12.4 to 14.9 gm/dl
- Women after middle age: 11.7 to 13.8 gm/dl
Anemia is a decrease in the amount of hemoglobin and red blood cells. Anemia is a relatively normal finding in pregnancy. Plasma is the watery, noncellular component of blood. In pregnancy, there is an increase in plasma volume of the blood in order to help supply oxygen and nutrients to mother and baby. There can be a 20% increase in the total number of red blood cells but the amount of plasma increases even more causing dilution of those red cells in the body. A hemoglobin level of pregnancy can naturally lower to 10.5 gm/dL representing a normal anemia of pregnancy.
What are the symptoms of anemia during pregnancy?
Nevertheless, the body needs a minimum amount of hemoglobin to supply the oxygen needs of the body and if it is lacking, the symptoms of anemia may occur. Symptoms of anemia include feeling increasingly tired, weak, short of breath with activity or at rest, a rapid heart rate, and a pale appearance to the skin. Lightheadedness or dizziness may occur when standing up too quickly or trying to physically exert. Symptoms occur because the body's oxygen requirements cannot be met by a decreased amount of hemoglobin contained in the fewer number of red blood cells.
If the pregnant mother had heavy prepregnancy menstrual flow, she may be anemic entering the pregnancy and the normal physiology of carrying a growing baby may make the anemia more pronounced. If there are two pregnancies close together, the mother's body may not yet have recovered, increasing the chances for anemia. It also can be difficult getting enough nutrition and iron with morning sickness. And the risk of anemia in pregnancy is even greater with multiple pregnancies, such as twins or triplets.
Anemia in pregnancy is common, but it is also frequently preventable through optimal diet and nutrition. The key is loading up on foods that are high in iron content like dark green leafy vegetables, eggs, and meat. As well, many foods like cereals and bread are iron fortified. If that doesn't work the health care professional may suggest an iron supplement to help replenish the body's stores. But in addition to iron, the body needs other building blocks to help make red blood cells including folic acid, which is an important vitamin to take to prevent potential damage to the growing baby's brain and spinal cord (neural tube defects).
A mother's physiology usually adapts well to the needs of a growing baby. Eating wisely can help the body cope with the physiology changes that are required. Eating wisely can, as a result, prevent the tiredness and weakness that can often accompany anemia. Basically, a healthy mother makes a healthy baby.
Medically reviewed by Wayne Blocker, MD; Board Certified Obstetrics and Gynecology
Evans, Arthur T., et al. Manual of Obstetrics. 7th ed. Philadelphia: Lippincott Williams & Wilkins, 2007.