Spectrophotometric normal values for fetal hemoglobin in relation to gestational age

Background The proportion of fetal hemoglobin (HbF) in preterm and term inf ants in relation to gestational age is important for establishing optimal t ransfusion strategies. Spectrophotometry allows HbF to be determined in sma ll blood samples drawn for total hemoglobin and oxygen saturation measureme nts. In the present study, we investigated a large number of preterm and te rm neonates to obtain normal values for different age groups. Methods In samples from 239 infants in our neonatal intensive care unit, we measured HbF as a percentage of total hemoglobin on the first day of life using the spectrophotometer OSM3 (cross-sectional study). In 80 neonates, t he HbF fraction of total hemoglobin was determined every week (longitudinal study). Subgroups of small-for-gestational-age (SCA) infants, and infants of pre-eclamptic and smoking mothers were compared with neonates appropriat e for gestational age (ACA). Results There was no difference in the decrease of HbF in relation to gesta tional age between the cross-sectional and longitudinal groups, i.e. modern intensive care did not alter the kinetics of HbF decrease. SGA infants and infants of pre-eclamptic mothers showed a delay in HbF decrease. Compared to earlier studies, the decrease of HbF was delayed. Conclusions As sick preterm and term neonates have HbF levels above 60%, tr ansfusion with adult blood might be beneficial in improving oxygen delivery .