Changes in hemoglobin F levels in pregnant women unaffected by clinical fetomaternal hemorrhage

► Mean maternal %Hb F level declined significantly during pregnancy. ► Mean maternal %Hb A1c level did not change significantly over the study period. ► The effect of %Hb A1c level < 10.0% on %Hb F measurements was clinically negligible. ► Our data may provide reference intervals of % Hb F during pregnancy.