Last Updated on February 20, 2025 by Analgesia team
Fetal Hemoglobin
HbF is the medical abbreviation for fetal hemoglobin, which is the primary type of hemoglobin in a fetus during pregnancy and early infancy:
-
Production
Erythroid precursor cells produce Fetal Hemoglobin from 10 to 12 weeks of pregnancy until the first six months after birth.
-
Levels
At birth, babies typically have half HbF and half adult hemoglobin (HbA). HbF levels usually drop to very low amounts about six months after birth.
-
Blood disorders
In adults or children, higher levels of HbF can indicate a blood disorder, such as:
- Thalassemia
- Myeloid leukemia
- Sickle cell anemia
- Thalassemia
-
Sickle cell anemia
HbF is a major genetic modulator of sickle cell disease. Some patients with sickle cell anemia have high levels of HbF, which can be associated with milder disease.
In the context of sickle cell disease, “fetal hemoglobin” refers to a type of hemoglobin that can significantly mitigate the severity of the disease by preventing the polymerization of sickle hemoglobin (HbS). It helps to act as a protective factor against the characteristic sickling of red blood cells; higher levels of fetal hemoglobin are associated with milder symptoms in sickle cell patients.Key points about fetal hemoglobin and sickle cell:-
Protective mechanism:Fetal hemoglobin does not readily participate in the formation of sickle hemoglobin polymers, which are responsible for the characteristic sickle shape of red blood cells in sickle cell disease.
-
Genetic variation:The amount of fetal hemoglobin produced varies between individuals, with some sickle cell patients naturally having higher levels of HbF, leading to a milder disease course.
-
Therapeutic target:Researchers are actively investigating ways to increase fetal hemoglobin production in sickle cell patients through medications or gene therapy, as higher HbF levels can significantly improve clinical outcome
-
-
Hereditary persistence of fetal hemoglobin (HPFH)High Fetal Hemoglobin levels can be caused by β-globin gene deletions or point mutations in the promoters of the HbF genes. This phenotype is called HPFH