Which embryonic hemoglobin is normally found in newborns?

In newborns, the predominant form of hemoglobin is hemoglobin F (Hb-F). This type of hemoglobin is crucial during fetal development as it has a higher affinity for oxygen compared to adult hemoglobin (Hb-A). This higher affinity allows for efficient transfer of oxygen from the mother’s blood to the developing fetus in the womb.

After birth, Hb-F will gradually be replaced by Hb-A as the infant grows and begins to rely on its own respiration and oxygenation. Typically, the transition from Hb-F to Hb-A occurs over the first few months of life.

Understanding the role of Hb-F is essential, as it plays a critical role in the developing fetus's oxygen transport. It's also worth noting that while other types of hemoglobin such as Hb-S and Hb-C are associated with certain disorders (like sickle cell disease and hemoglobin C disease, respectively), they are not normally present in significant amounts in healthy newborns. Hb-A is the adult form of hemoglobin but is not predominant in the newborn stage. Thus, the presence of Hb-F in newborns is a key aspect of normal hematological development.