<prompt> Barts hydrops fetalis is lethal becauseHb Barts cannot bind oxygenHb Barts cannot release oxygen to fetal tissuesMicrocytic red cells become trapped in the placentalThe excess a - globin form insoluble precipitates  <response>: Bart hydrops fetalis is a lethal complication of alpha thalassemia trait where oxygen cant release from hemoglobin 