Correlation between nucleated red blood cell count and early brain injury in perinatal asphyxia newborns

Abstract

Objective To explore the correlation between nucleated red blood cell(NRBC) count and early brain injury in perinatal asphyxia newborns. Methods A total of 140 full-term newborns who were born in Department of Obstetrical, First People's Hospital of Chenzhou, South China University, from May 1, 2011 to October 1, 2013 were chosen as study subjects.They were divided into perinatal asphyxia group(n=55) and normal group(n=85)in accordance with whether had perinatal asphyxia. And also according to neonatal hypoxic ischemic encephalopathy(HIE) diagnostic criteria for judging whether had encephalopathy, perinatal asphyxia group was further divided into four subgroups: severe encephalopathy subgroup(n=6), moderate encephalopathy subgroup(n=7), mild encephalopathy subgroup(n=12)and no encephalopathy subgroup (n=30). The umbilical arterial blood and heel peripheral blood within 1-4 d after birth of newborns were collected, and NRBC numbers were counted.And the Gessell development quotient was determined after 3 months' follow-up.The different levels of NRBC count were compared among different groups and subgroups with statistical method, and the correlation between umbilical arterial blood NRBC count and Gesell developmental quotient was analyzed.There were no statistically significant differences between perinatal asphyxia group and normal group in constituent ratio of gender and delivery mode, body weight at birth, gestational age and mother's age of newborns(P>0.05). The study protocol was approved by the Ethical Review Board of Investigation in Human Being of First People's Hospital of Chenzhou, South China University.Informed consent was obtained from the parents of each participant. Results ①The NRBC count of umbilical arterial blood in perinatal asphyxia group was significantly higher than that in normal group, while pH value of blood gas analysis was significantly lower than that in normal group, and the differences were statistically significant(t=5.52, 7.18; P<0.001). ②Compared umbilical arterial blood NRBC count in each subgroup of perinatal asphyxia group(no encephalopathy and mild, moderate, severe encephalopathy subgroup), there was no significant difference between mild and moderate encephalopathy subgroups (t=1.44, P=0.172); and compared the rest subgroups each other, NRBC count of severer degree subgroup was significantly higher than that in lighter degree subgroup, and the differences were statistically significant (P<0.05). ③Compared mean NRBC count within four days after birth from heel peripheral blood, there was no statistically significant difference between mild and moderate encephalopathy subgroups (t=0.36, P=0.985), and compared the rest groups (including perinatal asphyxia subgroups and normal group) each other, NRBC count of severer degree subgroup was significantly higher than that in lighter degree subgroup, and the differences were statistically significant(P<0.05). Compared heel peripheral blood NRBC count in the same group, each subgroup of perinatal asphyxia and normal group all showed significantly lower than the age of earlier one day, and the differences were statistically significant(P<0.05). NRBC counts had downward trend with the increase of postnatal day age.④On all newborns followed up 3 months, Gesell developmental quotient of perinatal asphyxia group was significantly lower than that of normal group, and the difference was statistically significant(t=4.52, P<0.001). There was negative correlation between developmental quotient and umbilical arterial blood NRBC counts(r=-0.85, P<0.05). Conclusions NRBC counts are associated with the degree of early brain injury of perinatal asphyxia newborns, and have certain value in evaluating the prognosis of neonatal brain injury. Key words: Asphyxia; Erythroblasts; Hypoxia-ischemia, brain; Infant, newborn