Prediction of perinatal asphyxia with nucleated red blood cells in cord blood of newborns.

Objective: To determine normal level of nucleated red blood cells (NRBC) per 100 white blood cells (WBC) in cord blood of term non-asphyxiated newborns and to investigate variations in NRBC counts in perinatal asphyxia.

Methods: A total of 75 cases were studied. Levels of NRBC per 100 WBC in umbilical venous blood were compared between 26 asphyxiated newborns (group I) and 49 non-asphyxiated newborns (group II). Correlation with neonatal outcome was also evaluated.

Results: The mean (+/-S.D.) NRBC per 100 WBC level in umbilical blood of newborns in group I was 16.5+/-6.4, range 3-25; whereas that in group II was 8.6+/-7.01, range 1-26. This difference was statistically significant (P<0.001). A statistically significant negative correlation existed between NRBC level and markers of acute intrapartum asphyxia, Apgar score and umbilical arterial pH (r=-0.50, P<0.001 and r=-0.48, P<0.001, respectively). Positive correlation was demonstrated with evidence of chronic antepartum asphyxia, presence of pregnancy induced hypertension and intrauterine growth restriction (r=2.66, P=0.02). A high NRBC count in umbilical blood correlated with poor early neonatal outcome.

Conclusions: The level of NRBC per 100 WBC correlates both with acute as well as chronic antepartum asphyxia. Further, it can be used as a reliable index of early neonatal outcome.