What is the most common type of Hb in neonates?

What is the most common type of Hb in neonates?

• A. Hemoglobin A
• B. Hemoglobin F
• C. Hemoglobin C
• D. Hemoglobin S

Answer: (D)

In newborns, fetal hemoglobin (HbF) is the dominant form. HbF has two alpha and two gamma chains, which gives it a higher affinity for oxygen than adult hemoglobin. This higher affinity facilitates transfer of oxygen from the mother across the placenta to the fetus. After birth, the production shifts from gamma to beta chains, and HbA becomes the majority within a few months. So, the neonate’s blood most commonly contains HbF. Hemoglobin S would only be present in infants with sickle cell disease or trait, and hemoglobin C is a variant not predominant at birth.

In newborns, fetal hemoglobin (HbF) is the dominant form. HbF has two alpha and two gamma chains, which gives it a higher affinity for oxygen than adult hemoglobin. This higher affinity facilitates transfer of oxygen from the mother across the placenta to the fetus. After birth, the production shifts from gamma to beta chains, and HbA becomes the majority within a few months. So, the neonate’s blood most commonly contains HbF. Hemoglobin S would only be present in infants with sickle cell disease or trait, and hemoglobin C is a variant not predominant at birth.