What is the cause of polycythemia in the fetus?
◦ Fetal hemoglobin has a greater affinity for oxygen as a result of diphosphoglycerate (DPG).
◦ The fetus has a different hemoglobin structure of two α- and two γ-chains rather than two α-and two β-chains.
◦ Increased erythropoiesis occurs in response to the hypoxic intrauterine environment.
◦ The lungs of the fetus are undeveloped and unable to diffuse oxygen adequately to the pulmonary capillaries.