NUCLEATED RED-BLOOD-CELLS - AN UPDATE ON THE MARKER FOR FETAL ASPHYXIA

OBJECTIVE: Our goal was to update our experience with nucleated red bl ood cells as a marker for fetal asphyxia and to determine whether a re lationship exists between the presence of nucleated red blood cells an d long-term neurologic impairment. STUDY DESIGN: Nucleated red blood c ell data from 153 singleton term neurologically impaired neonates were compared with cord blood nucleated red blood cells of 83 term nonasph yxiated newborns. Newborns with anemia, intrauterine growth restrictio n, and maternal diabetes were excluded. The group of neurologically im paired neonates was separated into the following subgroups: group I, p ersistent nonreactive fetal heart rate pattern from admission to deliv ery (n = 69); group II, reactive fetal heart rate on admission followe d by tachycardia with decelerations and absent variability (n = 47); g roup III, reactive fetal heart rate on admission followed by an acute prolonged deceleration (n = 37). The first and highest nucleated red b lood cell value and the time of nucleated red blood cell disappearance were assessed. RESULTS: The mean number of initial nucleated red bloo d cells was significantly higher in the group of neurologically impair ed neonates (30.3 +/- 77.5, range 0 to 732 per 100 white blood cells) than in the control group (3.4 +/- 3.0, range 0 to 12 per 100 white bl ood cells) (p < 0.000001). When the group of neurologically impaired n eonates was separated on the basis of timing of the neurologic impairm ent, distinct nucleated red blood cell patterns were observed. Signifi cant differences were obtained between each of the three groups of neu rologically impaired neonates and the normal group, with respect to in itial nucleated red blood cells (group 1, 48.6 +/- 106.9; group II, 11 .4 +/- 9.8; group III, 12.6 +/- 13.4; p less than or equal to 0.000002 ). Maximum nucleated red blood cell values were higher in group I (mea n 51.5 +/- 108.9) than in groups II and III combined (mean 12.7 +/- 11 .9) (p = 0.0005). Group I also had a longer clearance time (119 +/- 12 3 hours) than groups II and III combined (mean 59 +/- 64 hours) (p < 0 .001). CONCLUSION: Our ongoing study indicates that nucleated red bloo d cells identify the presence of fetal asphyxia. When fetal asphyxia i s present, distinct nucleated red blood cell patterns are observed tha t relate to the timing of fetal injury. In general, intrapartum injuri es are associated with lower nucleated red blood cell values. Thus our data continue to support the concept that nucleated red blood cell le vels may assist in determining the timing of fetal neurologic injury.