分娩方式对新生儿脐血儿茶酚胺水平的影响

The influence of mode of delivery on the level of catecholamines in umbilical cord blood of neonates

目的比较不同分娩方式对新生儿脐动、静脉血浆儿茶酚胺类激素水平的影响。方法新生儿共150例，分为正常新生儿组（90名）及胎儿窘迫组（60例）。再根据分娩方式的不同分为5组，各30例，分别为阴道分娩组、分娩镇痛组、择期剖宫产组、阴道助产组（施行低位产钳助产术）和急诊剖宫产组。于胎儿娩出断脐后立即采集脐动、静脉血各3ml，分别置于抗凝管中，即刻离心，分离血浆，采用酶联免疫吸附剂测定（ELISA）法分别测定血浆去甲肾上腺素（NE）、肾上腺素及多巴胺的水平。结果（1）各组脐动脉血NE及肾上腺素水平差异均有统计学意义（均P〈0．01），其中阴道助产组最高[（73±6）ng／L，（37．8±1．8）ng／L]，其次为急诊剖宫产组、阴道分娩组及分娩镇痛组，择期剖宫产组最低[（35±5）ng／L，（27．2±1．2）ng／L]。多巴胺水平阴道助产组[（33．7±4．5）ng／L]及急诊剖宫产组[（32．9±4．5）ng／L]高于其他各组，差异均有统计学意义（均P〈0．01）；（2）各组脐静脉血NE及肾上腺素水平差异均有统计学意义（均P〈0．01），且高低顺序与脐动脉一致。阴道助产组及急诊剖宫产组多巴胺水平比其他各组高，差异均有统计学意义（均P〈0．01）。（3）无论脐动、静脉，胎儿窘迫组NE、肾上腺素、多巴胺水平均高于正常新生儿组，差异有统计学意义（P〈0．01），胎儿窘迫组生后1、5及10minApgar评分均低于正常新生儿组，差异有统计学意义。结论对于无剖宫产指征的个体，阴道分娩可提高新生儿脐血儿茶酚胺类激素的水平，分娩期自控硬膜外镇痛可抑制新生儿应激反应；与正常新生儿相比，胎儿窘迫者脐血儿茶酚胺水平较高，既是新生儿提高自身对缺氧耐受力的表现，也是其缺氧状态的客观反映。

Objective To determine whether mode of delivery is associated with the level of catecholamines in umbilical cord blood of neonates. Methods A study was carried out on 150 neonates. Among them 90 were healthy while 60 were diagnosed fetal distress. Then the subjects were first divided into 5 groups according to different modes of delivery ： 30 were delivered by spontaneous labor for vaginal delivery without any pain relief; 30 by vaginal delivery with epidural anaesthesia; 30 by caesarean section without labor; 30 by vaginal delivery with low forceps because of fetal distress and 30 by caesarean section of emergency because of fetal distress. After delivery, umbilical cord blood of both artery and vein was collected for determination of norepinephrine （NE）, epinephrine（E）, and dopamine （DA）. Results （1） The concentration of NE and E of umbilical artery were different in each group （P 〈0. 01 ） , the group with the highest concentrations of NE and E was the ones delivered by vaginal delivery with low forceps[ （73 ± 6 ） ng/L, （37.8 ± 1.8） ng/L3 while caesarean section [ （35 ± 5 ） ng/L, （27. 2 ± 1.2） ng/L3 was associated with significantly lower concentrations of NE and E of umbilical artery. The ones delivered by vaginal delivery with low forceps[ （33.7 ±4. 5） ng/L] and caesarean section of emergency [ （32. 9 ±4. 5） ng/Lj had higher concentrations of DA compared with any other group （P 〈 0. 01 ） . （2） The concentration of NE and E of umbilical vein were different in each group （P 〈0. 01 ） just like that of umbilical artery. The ones delivered by vaginal delivery with low forceps and caesarean section of emergency had higher concentrations of DA compared with any other group （P 〈0. 01 ） . （3） The neonates with fetal distress had higher levels of catecholamine both in umbilical artery and umbilical vein than the healthy ones （ P 〈 0. 01 ） ; at the same time, the ones with fetal distress got lower Apgar scores 1, 5, 10 rain after born contrasted to the healthy ones. Conclusions If no indication for caesarean section exists, delivery by vaginal naturally can give higher level of catecholamines in cord blood, thus the neonate can get ready to adapt to the new environment better.