In newborns, fetal hemoglobin is nearly completely replaced by adult hemoglobin by approximately 6 months postnatally, except in a few thalassemia cases in which there may be a delay in cessation of HbF production until 3-5 years of age.
Fetal hemoglobin is nearly completely replaced by adult hemoglobin by approximately 6 months postnatally. This was except in a few thalassemia cases in which there may be a delay in cessation of HbF production until 3-5 years of age. This was in newborns.