Early diagnosis of perinatal asphyxia by nucleated red blood cell count: a case-control study.

BACKGROUND Perinatal asphyxia is a major cause of neurologic morbidity and mortality. The purpose of this study was to investigate variations in nucleated red blood cell (NRBC) count per 100 white blood cells (WBC) and absolute NRBC/mm3 in blood associated with perinatal asphyxia and its relationship to both the severity and short term prognosis of asphyxia. METHODS A prospective (case-control) study was undertaken between October 2006 and December 2008, in the Neonatal Intensive Care Unit, Ghaem Hospital, Mashhad, Iran. A total of 91 infants completed the study. Levels of nucleated red blood cell per 100 white blood cells and absolute nucleated red blood cell counts in venous blood were compared for 42 asphyxiated (case group) and 49 normal neonates (control group). These parameters were also related to the severity of asphyxia and clinical outcome. RESULTS The NRBC/100 WBC and absolute nucleated red blood cell levels in the blood of newborns in the control group were 3.87+/-5.06 and 58.21+/-87.57/mm3, respectively; whereas the corresponding values in the cases were 18.63+/-16.63 and 634.04+/-1002/mm3, respectively (P<0.001). A statistically significant negative correlation existed between nucleated red blood cell level and indicators of the severity of perinatal asphyxia, first minute Apgar score and blood pH (P<0.001), respectively. A positive correlation was demonstrated between these parameters and severity of asphyxia, acidosis, and poor outcome (P<0.05). CONCLUSION The NRBC/100 WBC and/or absolute nucleated red blood cell are simple markers for assessment of severity and early outcomes of perinatal asphyxia.