Clinical and hematological features of Hb Bart’s hydrops fetalis. (A) Peripheral blood smear of an infant showing immature red cell precursors, hypochromic microcytosis, and anisopoikilocytosis. (B) Starch gel electrophoresis of hemolysates from a normal adult (lane 1); an individual with HbH disease (lane 2), and the cord blood of an infant with Hb Bart's hydrops fetalis (lane 3). Reproduced with permission, with minor modifications from Higgs¹³ and Pressley et al.¹⁴