| Objective:The incidence of serious complications of premature babies has been increased along with the increasing number of premature neonates as the development of assisted reproductive technology and the needs of human society.Recently,it has been discovered that cord blood hematopoietic stem / progenitor cells can enter damaged tissues by paracrine,producing anti-inflammatory and immunomodulatory factors,and can differentiating into microglia,liver cells,and type II alveolar cells.Also,umbilical cord blood hematopoietic stem cell transplantation owns unique advantages of low incidence of graft-versus-host disease and weak immunogenicity.Thus it is expected to become a new method for treating serious complications of newborns.At present,there are more clinical studies on cord blood in term neonates,but fewer studies on preterm neonates.Therefore,we compared the total number of nucleated cells(Total Nucleated Cell,TNC)and CD34+hematopoietic stem /progenitor cells which is an important indicator of umbilical cord blood quality in different gestational age to explore the possibility of using umbilical cord blood in preterm neonates,to provide a basis for autologous transplantation of umbilical cord blood stem cells in preterm infants.At the same time,other perinatal factors that may affect the total number of nucleated cells in the cord blood and CD34+ counts were analyzed as a reference for selection of cord blood banks.Methods: A prospective study in 130 deliveries occurring at Dalian Women and children' Medical Center between June 2019 and January 2020.There were 65 males and 65 females,with a male to female ratio of 1: 1.Factors including maternal age,blood type,gestational diabetes,pregnancy-induced hypertension,pregnancy method,delivery method,single / twin,newborn weight,sex,Apgar score after,and placenta,amniotic fluid,which may interfer our results,were collected.The cases were grouped according to the gestational age: group A(n = 10;189-237day),group B(n = 47;238-258day),C Group(n = 73;259-293day).The total number of nucleated cells in cord blood was counted with an automatic analyzer.Flow cytometry was used to detect CD34+% and then calculated CD34+ cells count.Statistical analysis was performed with SPSS Statistics 26.0.Results:1.There were differences in the number of CD34+ cells in cord blood hematopoietic stem cells in different gestational age groups.The number of CD34+ cells in group B was higher than group C,which was statistically difference(p <0.05).There was no significant difference between group A and group C,and no statistical difference between group A and group B,too(p> 0.05).2.Correlation analysis between gestational age and cord blood CD34+ cell number showed a negative correlation(p <0.05,r <0),and its regression equation is:Y=-0.037X+10.657(F=10.571,P<0.05).3.There was no significant difference in the total number of nucleated cells of umbilical cord blood hematopoietic stem cells in different gestational age groups(p>0.05).Correlation analysis between gestational age and total number of nucleated cells in cord blood showed no significant correlation(p> 0.05).4.Other perinatal factors: maternal age,blood type,gestational diabetes mellitus,pregnancy-induced hypertension syndrome,pregnancy pattern,delivery pattern,single /twin,neonatal weight,gender,Apgar score after birth,placental shape,amniotic fluid Pollution,umbilical cord around the neck or other parts of the body,there was no significant difference in the number of TNC of cord blood between grouped variables,and there was no significant correlation between continuous variables and the number of TNC umbilical cord blood nucleated cells(p> 0.05).5.There were no significant differences in the number of CD34~+ cells among maternal blood types,gestational diabetes,gestational hypertension,pregnancy patterns,delivery patterns,single / twin births,gender,Apgar score,placenta,amniotic fluid,and umbilical cord after birth.0.05),no correlation with neonatal weight(p> 0.05),and positive correlation with maternal age(p <0.05,r> 0).6.Multivariate analysis suggested that gestational age and maternal age were independent influencing factors of cord blood CD34+(p <0.05).Conclusions:1.The number of CD34~+ cells in umbilical cord blood hematopoietic stem cells is not less than in preterm infants than in term infants.2.The number of umbilical cord blood hematopoietic stem cells CD34+ cells decreases with gestational age increases.The regression equation between gestational age and CD34+cells is:Y=-0.037X+10.657.3.The number of cord blood CD34+ cells in cord blood is positively correlated with maternal age.4.The number of TNC in cord blood of premature infants is not less than that of term infants.5.Multivariate analysis proved that gestational age and maternal age were independent influencing factors of cord blood CD34~+ cell count. |
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