Development of Hemoglobin Developmental Hemoglobin Hemoglobin Stage Composition Embryo Hb Gower Hb Gower Hb Portland A 272 Fetus HbF Adult Hb a a2p2 Hb a asDevelopmental Stage Hemoglobin Hemoglobin Composition Embryo Hb Gower1 2 2 Hb Gower2 2 2 Hb Portland 2 G 2 2 A 2 Fetus Hb F 2 G 2 2 A 2 Adult Hb A 2 2 Hb A2 2 2 Development of Hemoglobin