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

Abstract: Background: Complete automation of high-performance liquid chromatography (HPLC) for determination of hemoglobin F (%Hb F) and hemoglobin A1c (%Hb A1c) levels has made this procedure available in many clinical laboratories. However, the physiological changes in %Hb F during pregnancy and the effects of physiological and supraphysiological levels of %Hb A1c on measurement of %Hb F have not been studied extensively. Methods: Simultaneous determination of %Hb F and %Hb A1c was conducted in 490 blood samples obtained before (n =21), during the 1st (n =150), 2nd (n =116), and 3rd (n =192) trimesters of pregnancy, and postpartum (n =11) from 357 women, including 60 women with hyperglycemia but unaffected by clinical fetomaternal hemorrhage, by HPLC. Results: Mean (SD) Hb F levels were 0.71% (0.25%) before pregnancy. The value of 0.82% (0.47%) during the 1st trimester decreased significantly to 0.66% (0.35%) during the 2nd trimester and to 0.58% (0.38%) during the 3rd trimester. The level was 0.62% (0.31%) approximately one year after delivery. Thus, %Hb F was highest during the 1st trimester of pregnancy. The effects of varied %Hb A1c levels on %Hb F measurements were clinically negligible. Conclusions: The data presented in this work may be used as reference intervals of %Hb F determined with HPLC during pregnancy. [Copyright &y& Elsevier]