Hydroxyurea treatment helps the red blood cells stay round and fl exible. This lets them travel more easily through tiny blood vessels. In part, this happens because hydroxyurea increases the amount of fetal hemoglobin (Hb F) in red blood cells. Newborn babies have Hb F when they are born. Hb F helps protect them from sickle cell complications (health problems) during the fi rst few months of life. With an increased amount of Hb F, red blood cells are less likely to change into the sickle or banana shape. In most people, the amount of Hb F decreases.
