影响新生儿脐血β内啡肽水平的多因素分析

Multi-factor analysis of umbilical plasma β-endorphin levels in neonates

目的 研究不同妊娠、分娩因素对脐血β内啡肽 (β-EP)水平的影响。 方法 收集不同孕期的新生儿脐血共95例,用放射免疫法测定其β-EP水平,以β EP为因变量,以新生儿胎龄、性别、出生体重、分娩方式、母患高血压、母患糖尿病、宫内窘迫、胎膜早破为自变量,进行多元线性逐步回归,筛选出可能的影响因素,进一步研究不同影响因素时脐血β-EP变化。 结果 胎龄、分娩方式、宫内窘迫是影响脐血β-EP水平的重要因素(P均<0.05)。早产儿组脐血β EP值高于足月儿组,分别为(409.5±150.1)pg/ml、(261.4±141.5)pg/ml,差异均有统计学意义(P均<0.05)。阴道分娩组及产钳助产组高于选择性剖宫产组,差异有统计学意义(P均<0.05)。阴道分娩组与产钳助产组比较,差异无统计学意义(P均>0.05)。宫内窘迫组高于无宫内窘迫组,差异有统计学意义(P均<0.01)。 结论 分娩应激、疼痛会使β-EP升高,缺氧是影响β-EP水平的一个重要因素,脐血β-EP水平可作为胎儿缺氧的一个指标。早产儿脐血β EP高于足月儿是否是早产儿易发生呼吸暂停的病理生理基础,有待进一步研究。

Objective To study the levels of umbilical plasma β-endorphin (β-EP) in normal and abnormal pregnancy and the influencing factors. Methods The umbilical plasma β-EP concentrations of 95 cases were measured by radioimmunoassay. Linear regression was used to find out the influencing factors of β-EP including: neonatal gestational age, gender, birth weight, mode of delivery, maternal hypertension, maternal diabetes, premature rupture of membranes(PROM) and fetal distress. The subjects were divided into two groups: healthy term newborns and preterm neonates. Results Gestational age, mode of delivery and fetal distress were important factors influencing umbilical blood β-EP production (P<0.05), whereas gender, maternal hypertension, diabetes and PROM were not. The preterm group showed higher umbilical plasma β-EP level than that of the term group [(430.5±229.2) pg/ml vs (409.3±150.1) pg/ml, P<0.05]. The values in neonates of vaginal and forceps delivery were significantly higher than those delivered by cesarean section[(37.4±1.4) pg/ml and (386.5±201.6) pg/ml vs (255.9±153.6) pg/ml; P<0.05]. The β-EP level of neonates with fetal distress was significantly higher than those without [(409.3±105.1) pg/ml vs (242.2±180.0) pg/ml, P<(0.01].) Conclusions Stress during delivery and hypoxia are important factors of increasing the synthesis of β-EP. β-EP may be an indicator of chronic neonatal hypoxia. Preterm neonates presented a higher level of β-EP than full-term ones. It is to be determined that whether this is related to apnea of preterm newborns.