Cord blood nucleated red blood cell count - a marker of fetal asphyxia

Objectives : To study the cord blood nucleated RBC count (NRBC) in asphyxiated and nonasphyxiated fetuses at birth and to find out the correlation between NRBC count, fetal acidosis and the clinical markers of asphyxia. Methods : This is a prospective comparative study conducted between 2002 and 2004. Parturient women who were in labor between 37 and 42 weeks of gestation were selected after satisfying inclusion and exclusion criteria and divided in 2 groups. The control group consisted 51 cases with nonasphyxiated fetuses and study group 52 asphyxiated fetuses. The cord blood was collected soon after birth, one sample for pH determination and the other sample for making smears that were stained with Leishman’s stain. NRBCs were counted against 100 WBCs. The statistical analysis was done using SSPS and Chi-square test to find out the relationship between pH and NRBC count and the correlation between NRBC count, and meconium stained amniotic fluid (MSAF), nonreassuring fetal heart rate pattern and low apgar scores. Results : The mean NRBC count in the study group was 25.65 ± 10.14 as compared to 12.33 ± 5.51 in the control group (p=0.003). The NRBC count was significantly higher in MSAF and in neonates with low apgar scores of < 6 at 5 minutes (P=0.02). Conclusion : Acidotic neonates (cord blood pH < 7.1) at birth had higher mean NRBC count compared to nonacidotic neonates and hence NRBC count of cord blood smear serves as a good indicator of fetal asphyxia.