: Fetal Hemoglobin, Blood, Measured

: What Is Fetal Hemoglobin?

: Hemoglobin is the protein in red blood cells that carries oxygen. Fetal hemoglobin, or hemoglobin F, is the main oxygen-carrying hemoglobin before birth and is gradually replaced by adult hemoglobin after birth. Most older children and adults have only small amounts of fetal hemoglobin remaining.

: Why This Test Is Done

: A fetal hemoglobin measurement may be ordered to help assess inherited blood disorders such as thalassemia or sickle cell disease, to evaluate certain types of anemia, or to monitor conditions in which fetal hemoglobin levels are unusually high. It can also be used as part of follow-up when abnormal hemoglobin is found.

: How the Sample Is Collected

: The test is usually performed on a blood sample drawn from a vein, typically from the arm. The specimen may be analyzed by a laboratory method that separates and measures the different hemoglobin types present.

: What the Results Mean

: Results are interpreted alongside your age, symptoms, family history, and other blood tests. A higher-than-expected fetal hemoglobin level may occur in several inherited and acquired conditions, so the result is considered together with the full clinical picture rather than on its own.