Hemoglobin (Fetal)

Does this test have other names?

Hemoglobin F, alkali-resistant hemoglobin, high performance liquid chromatography (HPLC), HbF

What is this test?

This test checks the amount of fetal hemoglobin (HbF) in the blood. Fetal hemoglobin is one of many types of hemoglobin. A baby growing in the womb has high levels of HbF. The level of HbF usually drops to tiny amounts about 6 months after birth. In an adult or child, a higher level of HbF can mean you have a blood disorder. These include thalassemia, myeloid leukemia, and sickle cell anemia.

Why do I need this test?

You may need this test if your doctor thinks that you may have a blood disorder related to a high level of HbF or to keep track of therapy if you are on hydroxyurea drug for sickle cell disease. People with most of these disorders don't have symptoms. But may have anemia. Symptoms of anemia can include fatigue, pain, irregular heartbeat, and other heart problems.

The blood disorders are genetic. Because of this, you may need this test if you have a family history of one of these diseases.

What other tests might I have along with this test?

You may also have a blood smear, iron studies, or DNA analysis. These tests can also diagnose blood disorders related to HbF.

What do my test results mean?

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your doctor what your test results mean for you.

Healthy adults usually only have HbF in tiny amounts. If your amount is higher, you may have a blood disorder, such as thalassemia or sickle cell anemia. Or you may have another condition related to high levels of HbF. 

How is this test done?

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand. 

Does this test pose any risks?

Having a blood test with a needle has some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore. 

What might affect my test results?

If you have higher than normal levels of HbF, you may have anemia, leukemia, or a sickle cell disorder. But this test alone does not tell which condition you might have. Some people with higher levels of HbF don't have any symptoms. More testing is needed to find out the type of your blood disorder.

How do I get ready for this test?

You don't need to prepare for this test. Tell your doctor about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.