脐血清皮质醇和硫化脱氢表雄酮在足月分娩时的作用

目的　探讨脐血清皮质醇和硫化脱氢表雄酮在足月分娩时的作用。方法　采用放射免疫法测定 10 0例足月分娩新生儿脐血清中皮质醇和硫化脱氢表雄酮的含量 ,其中A组 18例 ,为无阵痛、选择性剖宫产产妇 ;B组 10例 ,为潜伏期剖宫产产妇 ;C组 12例 ,为活跃期剖宫产产妇 ;D组 60例 ,为阴道分娩产妇。结果　 (1)新生儿脐血清皮质醇含量随孕周增加而增加 ,至 3 9周时脐血清皮质醇含量达峰值 ,为 (2 86± 5 0 ) μg/L ,42周时 ,皮质醇含量下降 ,接近孕 3 7周水平 (194± 70 ) μg/L ,血清硫化脱氢表雄酮含量变化与之相平行 ,两者呈正相关 [相关系数 (r) =0 .46,P <0 .0 5 ]。 (2 )A、B、C组随着产程进展 ,皮质醇含量增加 ,硫化脱氢表雄酮含量不增加。 (3 )D组新生儿脐血清皮质醇含量较其他 3组高 (P <0 .0 1)。硫化脱氢表雄酮含量变化无差异。结论　脐血清皮质醇和硫化脱氢表雄酮在分娩发动和加速中起着重要作用     

阴道分娩与剖宫产的正常足月新生儿脐动脉血乳酸值的比较

目的 :探讨阴道分娩与剖宫产的足月正常新生儿脐动脉血乳酸值间的差异 ,及阴道分娩新生儿脐动脉血乳酸值与产妇第二产程时间的相关性。方法 :5 6例阴道分娩和 6 2例剖宫产的足月正常新生儿出生后立即取 2ml脐动脉血行乳酸检测。并对阴道分娩新生儿脐动脉血乳酸值与第二产程时间长短的相关性进行分析。结果 :阴道分娩组的脐动脉血乳酸水平明显高于剖宫产组 (P <0 0 1) ;但阴道分娩中第二产程≤ 45分钟 (10例 ) ,脐动脉血乳酸水平低于剖宫产组 (P <0 0 5 ) ;第二产程≤ 1小时 (2 8例 ) ,乳酸水平与剖宫产组比较 ,差异无显著性 (P >0 0 5 ) ;而第二产程 >1小时 (2 8例 ) ,乳酸水平高于剖宫产组 (P <0 0 5 )。阴道分娩新生儿乳酸水平与第二产程时间呈密切正相关 (P <0 0 1)。结论 :阴道分娩第二产程 <1小时与剖宫产比较新生儿乳酸值无差异 ;而当第二产程 >1小时 ,则使新生儿乳酸值增高。故对第二产程长应重视 ,并予积极处理。     

阴道分娩与剖宫产对母儿血清胃泌素水平的影响

目的　探讨经阴道分娩与剖宫产对母血和新生儿脐血胃泌素水平的影响。　方法　采用放射免疫法测定择期剖宫产、阴道分娩的孕妇及产后 3～ 5 d的产妇各 2 0例的血清胃泌素水平。同时测定 2 0例经阴道产儿和 2 2例剖宫产儿的脐血胃泌素水平。　结果　分娩发动后母血清胃泌素水平为 (10 8.2 3± 2 4.39) ng/ L ,较未发动宫缩的足月孕妇血清胃泌素水平 (78.2 8± 31.13) ng/ L升高(P<0 .0 5 ) ;产后 3～ 5 d母血清胃泌素水平为 (143.33± 35 .6 1) ng/ L ,较产前明显升高 (与阴道分娩和剖宫产相比分别为 P<0 .0 5 ;P<0 .0 1)。经阴道产儿脐血胃泌素水平为 (138.37± 2 0 .2 8) ng/ L ,明显高于剖宫产儿脐血胃泌素水平 (10 1.2 3± 18.16 ) ng/ L (P<0 .0 5 )。　结论　阴道分娩有利于新生儿胃肠功能的成熟与完善     

促肾上腺皮质激素释放激素、皮质醇和硫酸脱氢表雄酮在早产发动中的作用

目的探讨促肾上腺皮质激素释放激素（CRH）、皮质醇、硫酸脱氢表雄酮（DHEA—S）在早产发动中的作用。方法用原位杂交法检测早产阴道分娩产妇26例（早产组）、足月临产阴道分娩产妇29例（足月临产组）、足月未临产剖宫产产妇25例（足月未临产组）胎盘、胎膜组织中CRH mRNA的分布与表达,用放射免疫法测定3组产妇分娩的新生儿脐静脉血CRH,脐动脉血DHEA-S及皮质醇的含量。结果（1）各组产妇胎盘、胎膜组织中均可见CRH mRNA表达。（2）CRH mRNA在胎盘组织中表达的阳性指数：早产组为5．5±1．4,足月临产组为5．4±1．5,均高于足月未临产组的2．7±1．5。差异均有统计学意义（P〈0．01）;CRHmRNA在胎膜组织中表达的阳性指数：早产组为5．4±1．7,足月临产组为5．4±1．4,足月未临产组为2．0±1．4,早产组、足月临产组与足月未临产组比较,差异也有统计学意义（P〈0．01）;CRH mRNA在胎盘及胎膜中表达的阳性指数早产组与足月临产组比较,差异无统计学意义（P〉0．05）;各组产妇CRH mRNA在胎盘与胎膜组织中的表达比较,差异均无统计学意义（P〉0．05）。（3）早产组和足月临产组新生儿脐静脉血CRH含量分别为（7．8±3．3）、（7．7±4．1）ng／L,脐动脉血DHEA-S含量分别为（514±295）、（483±207）μg／L,均高于足月未临产组的（4．8±2．4）ng／L、（360±80）μg／L,差异有统计学意义（P〈0．05）;而早产组与足月临产组比较,差异则无统计学意义（P〉0．05）。早产组脐静脉血CRH含量与胎盘、胎膜组织中CRH mRNA的表达均呈正相关关系（r=0．935、0．853,P〈0．01）,足月临产组脐静脉血CRH含量与胎盘、胎膜组织中CRH mRNA的表达也呈正相关关系（r=0．902、0．825,P〈0．01）。（4）早产组新生儿脐动脉血皮质醇含量为（246±117）μg／L,明显高于足月临产组的（172±72）μg／L和足月未临产组的（127±60）μg／L,差异均有统计学意义（P〈0．05,P〈0．01）。早产组新生儿脐静脉血CRH与脐动脉血皮质醇、DHEA-S含量均呈正相关关系（r=0．523、0．424,P〈0．05）,足月临产组新生儿脐静脉血CRH与脐动脉血皮质醇、DHEA—S含量也呈正相关关系（r=0．438、0．354,P〈0．05）。结论（1）CRH与分娩发动密切相关,胎盘、胎膜组织中CRH mRNA表达升高可能是早产发动的重要原因。（2）DHEA—S、皮质醇与分娩的发动密切相关。     

蛛网膜下腔-硬膜外联合阻滞麻醉用于分娩镇痛206例分析

目的　探讨分娩镇痛的效果及对产程、母婴状况的影响。方法　采用蛛网膜下腔 -硬膜外联合阻滞(CSEA)用于分娩镇痛的产妇 2 0 6例作为观察组 ,将未采用任何分娩镇痛药物而进入产程的产妇 2 0 6例作为对照组 ,分别观察产程时间、分娩方式、产后出血、胎儿窘迫及新生儿窒息情况。结果　两组产程活跃期比较 ,有极显著性差异 (P <0 0 1) ;两组分娩方式比较有显著性差异 (P <0 0 5 ) ;两组胎儿窘迫、新生儿窒息及产后出血发生率比较 ,无显著性差异 (P >0 0 5 )。结论　CSEA用于分娩镇痛 ,疼痛阻滞完善 ,加速了产程活跃期及第二产程的进展 ,降低了剖宫产及阴道难产率 ,对母婴均无不良影响     

基质金属蛋白酶2、9及其特异性组织抑制剂在自发性胎膜早破发病中的作用

目的　探讨基质金属蛋白酶 (MMP) 2、9及其特异性组织抑制剂 (TIMP)在自发性胎膜早破发病中的作用。方法　采用RT PCR方法对 8例自发性胎膜早破患者 (胎膜早破组 )、8例正常阴道分娩产妇 (阴道分娩组 )以及 8例择期剖宫产产妇 (剖宫产组 )的胎膜组织中MMP 2、MMP 9和TIMP 2、TIMP 1mRNA的表达进行检测。结果　 (1)MMP 2 :胎膜早破组为 0 84 9± 0 0 37,阴道分娩组为 0 32 7± 0 0 2 3,剖宫产组为 0 30 7± 0 0 2 8。胎膜早破组MMP 2表达水平明显高于阴道分娩组和剖宫产组 ,两组比较 ,差异有统计学意义 (P <0 0 5 ) ;阴道分娩组MMP 2表达水平与剖宫产组比较 ,差异均无统计学意义 (P >0 0 5 )。 (2 )MMP 9:胎膜早破组为 0 0 2 6± 0 0 0 4 ,阴道分娩组为 0 0 0 8± 0 0 0 1,剖宫产组无表达。胎膜早破组MMP 9表达水平明显高于阴道分娩组 ,两者比较 ,差异有统计学意义 (P <0 0 5 )。 (3)TIMP 2 :胎膜早破组为 0 4 2 0± 0 12 2 ,阴道分娩组为 0 730± 0 14 8,剖宫产组为 0 885± 0 0 6 5。胎膜早破组TIMP 2表达水平明显低于阴道分娩组和剖宫产组 ,两者比较 ,差异有统计学意义 (P <0 0 5 ) ;阴道分娩组TIMP 2表达水平明显低于剖宫产组 ,两组比较 ,差异有统计学意义 (P <0 0 5 )。 (4)TI     

潜伏期硬膜外产时镇痛对母儿结局的影响

目的了解潜伏期硬膜外镇痛是否存在对母儿的不良影响。方法回顾性分析273例初产妇病历资料,潜伏期镇痛(潜伏期组)124例,活跃期镇痛(活跃期组)共149例作为对照组。比较两组产程经过、分娩方式及结局。结果两组的年龄、妊娠次数、分娩前一周内羊水指数、分娩孕周及新生儿体重无统计学差异。需人工破膜或催产素加强宫缩、产程中排尿困难需导尿处理和产后尿潴留的比例,及镇痛后下肢麻木、产后出血、胎心异常、羊水变化、脐动脉血pH异常的发生率和Apgar评分异常的比例两组均无差异。潜伏期组中阴道顺产、产钳、剖宫产分别为71(57·3%)、20(16·1%)、33(26·6%)例,活跃期组则分别为89(59·7%)、33(22·1%)、27(18·2%)例(P=0·169);阴道分娩者第一产程时间潜伏期组和活跃期组分别为(556·8±206·3)min和(558·5±198·4)min,(P=0·950),第二产程分别为(54·0±30·6)min和(53·1±36·4)min,(P=0·860),第三产程分别为(9·1±6·1)min,(8·1±6·5)min,(P=0·276),两组发生活跃期停滞、活跃期延长、第二产程延长和第二产程中胎位异常的比例均无统计学差异。两组产程图均位于Friedman产程图左侧,潜伏期组平均每小时宫口开大2·1cm,活跃期组每小时宫口开大1·8cm(P=0·091)。结论较活跃期镇痛比较,潜伏期镇痛未增加对母儿的不良影响;镇痛过程中的关键是注意药物浓度,镇痛起始时间应因人而异。     

子宫平滑肌间隙连接蛋白43、促肾上腺皮质激素释放激素、皮质醇与分娩发动的研究

目的:探讨临产前、后子宫平滑肌细胞间隙连接蛋白Cx-43的表达以及母血、脐血、羊水中促肾上腺皮质激素释放激素(CRH)、皮质醇(Cortisol)的水平变化,分析它们与分娩发动的关系。方法:应用免疫组化SABC法结合计算机图象分析技术分析60例足月妊娠产妇子宫下段平滑肌Cx-43的表达;用放射免疫方法测定产妇的静脉血、羊水及胎儿脐静脉血中CRH、Cortisol的含量。结果:临产组子宫肌细胞Cx-43的表达明显强于未临产组,差异有显著性(P<0.01)。临产组母血、脐血中CRH、Cortisol及羊水中Cor-tisol与临产前比较显著升高(P<0.01),且与子宫肌Cx-43蛋白的表达呈显著正相关(P<0.01);结论:CRH、Cortisol在分娩发动中起重要作用,并可能通过促进子宫平滑肌Cx-43的表达参与分娩发动。     

膜型基质金属蛋白酶表达与妊娠疾病的关系

目的 :研究葡萄胎和先兆子痫等与滋养层细胞密切相关的妊娠疾病在病理发生机制上与膜型基质金属蛋白酶表达的关系。方法 :采用逆转录多聚酶链反应 (RT PCR)检测方法 ,比较葡萄胎组织、早孕绒毛、先兆子痫足月胎盘和正常足月胎盘 (自然分娩和剖宫产 )组织中膜型基质金属蛋白酶 (MT MMP)的表达情况。结果 :5种胎盘绒毛组织均表达MT2 MMP和MT5 MMP。在相对表达量上 ,MT2 MMP及MT3 MMP在正常早孕绒毛组织中的表达强于葡萄胎组织 ,正常足月胎盘组织中MT2 MMP和MT5 MMP的表达也强于先兆子痫患者胎盘组织中 (P <0 .0 5 )。而自然分娩和剖宫产足月胎盘绒毛组织中MT2 MMP、MT3 MMP和MT5 MMP的表达差异均无显著性 (P >0 .0 5 )。结论 :MT2 MMP、MT3 MMP和MT5 MMP等膜型MMP在胎盘绒毛组织中的表达差异 ,与葡萄胎、先兆子痫等和滋养层密切相关的妊娠疾病的病理发生有关     

腰麻-硬膜外联合麻醉及硬膜外自控分娩镇痛始于产程潜伏期与活跃期的比较

目的 比较腰麻-硬膜外联合麻醉及硬膜外自控分娩镇痛始于产程潜伏期与活跃期的临床效果、对母婴应激反应的影响和脐带血中的罗哌卡因浓度. 方法 将80例于2009年1月至6月在首都医科大学附属北京友谊医院产科分娩且自愿接受分娩镇痛的足月、单胎、头位初产妇,随机分为潜伏期组和活跃期组(各40例),分别于潜伏期(宫口扩张0.5～2.5 cm)和活跃期(宫口扩张≥3.0 cm)于蛛网膜下腔给予罗哌卡因2 mg+芬太尼10 μg,随后采用0.1 ％ 罗哌卡因+芬太尼2 μg/ml硬膜外患者自控镇痛模式开始分娩镇痛,记录视觉模拟评分(visual analogue score,VAS)的镇痛评分、下肢肌力、产程时间、分娩方式、药物用量及产妇满意度,检测镇痛前、娩出胎儿即刻产妇静脉血和胎儿娩出后脐带血皮质醇浓度(放射免疫法)及脐带血罗哌卡因浓度(高效液相色谱法).以同期相同条件不接受分娩镇痛的40例产妇为对照组,采用x2或t检验和方差分析进行统计学比较.结果 (1)镇痛后5 min始至宫口开全过程中,潜伏期组和活跃期组VAS评分仅在宫口7.0～8.0cm及宫口开全时低于对照组[宫口7.0～8.0 cm:(2.9±1.4)分、(2.6±1.5)分与(9.2±0.7)分,F=201.50,P＜0.01;宫口开全:(4.7±2.2)分、(3.6±2.0)分与(9.1±0.7)分,F=62.07,P＜0.01].(2)胎儿娩出即刻母体血皮质醇浓度较镇痛前增高,但潜伏期组和活跃期组均比对照组增高幅度小[(761±125)μg/L、(731±184) μg/L与(902±172) μg/L,t=-3.491和-3.483,P均＜0.01],而潜伏期与活跃组2组间差异无统计学意义;3组间脐带血皮质醇浓度差异无统计学意义[(168±46) μg/L、(159±49) μg/L与(170±86) μg/L,F=0.23.P＞0.05].(3)胎儿娩出即刻潜伏期组和活跃期组脐带血罗哌卡因浓度分别为(0.21±0.10) mg/L和(0.20±0.03) mg/L(t=0.557,P＞0.05).(4)第一产程、第二产程时间,催产素使用率,新生儿体重,新生儿1 min、5 min Apgar评分3组间差异均无统计学意义(P均＞0.05).与对照组相比,潜伏期组和活跃期组自然分娩率较高(75.0％、85.0％与52.5％,P＜0.05)、剖宫产率较低(20.0％、15.0％与45.0％,P＜0.05),潜伏期组镇痛时间长于活跃期组[(215±143) min与(118±50) min,t=3.722,P＜0.01],芬太尼用量大[(28±11) μg与(17±6)μg,t=5.084,P＜0.01]. 结论 腰麻-硬膜外联合分娩镇痛能降低剖宫产率和母体应激反应,且不延长产程,不降低胎儿的应激水平;始于潜伏期并不明显增加脐带血药物浓度.     

Parturition-induced changes in maternal plasma cortisol levels.

Total maternal plasma cortisol levels were measured by a radioassay method in 9 patients who were in spontaneous labor and 10 patients who were electively induced at term with oxytocin. Determinations were made at onset of labor and repeated at full cervical dilatation. Total maternal plasma cortisol levels were also measured in 7 patients undergoing elective cesarean section without labor, determinations being made just prior to the procedure and at the time of uterine incision. Computerized analysis showed the mean initial cortisol level (+/- SE) in the spontaneous labor group (15.4 +/- 1.6 mug/100 ml) to be significantly less than the mean initial level of the group electively delivered by oxytocin induction (37.2 +/- 6 mug/100 ml), with P less than 0.01. The former value was also found to be significantly less than that of the group electively delivered by cesarean section (32.1 +/- 9.3 mug/100 ml), with P less than 0.05. A significant rise was noted at full cervical dilatation in the spontaneous labor group (P less than 0.05), whereas no change occurred in the two elective groups. No significant correlation was found between the maternal cortisol levels on the one hand and the cord cortisol levels. These findings indicate that a) maternal participation is unlikely in bringing about a surge of fetal plasma cortisol which is thought to precede spontaneous labor, b) elective termination of term pregnancy by oxytocin induction or cesarean section may be initially more stress-provoking to the mother than spontaneous labor, and c) maternal stress as measured by plasma cortisol level is not reflected in the fetus.     

Increased immunoreactive erythropoietin in cord plasma and neonatal bilirubin production in normal term infants after labor

The purpose of this investigation was to compare immunoreactive erythropoietin levels in umbilical cord plasma and neonatal bilirubin production in infants born of normal women who delivered with or without labor. Two groups of term (38 to 42 weeks) singleton pregnancies were compared: 1) those delivered by repeat elective cesarean section without prior labor (N = 17), and 2) those delivered vaginally or by cesarean section after labor (N = 24). None of the infants was asphyxiated, and there was no difference in Apgar scores between the no-labor and labor groups. The cord plasma erythropoietin levels were lower in the infants of women who had repeat elective cesarean section without labor than in those whose mothers had labor before delivery (Wilcoxon rank sum test, P less than .025). The median erythropoietin for the no-labor group was 22.9 mU/mL compared with 38.8 mU/mL for the labor group. The pulmonary excretion rate of carbon monoxide (VeCO), an index of bilirubin production, for the no-labor group was 14.3 +/- 6.2 SD microL/kg per hour compared with 18.0 +/- 4.9 SD microL/kg per hour for the labor group (P less than .05). The hemoglobin concentration for the no-labor group was 16.0 +/- 1.5 SD g/dL compared with 17.7 +/- 2.2 SD g/dL for the labor group (P less than .05). The VeCO correlated with the hemoglobin concentration (N = 32, r = 0.37, P less than .05). The results of the present study suggest that labor is normally associated with increases in the cord plasma erythropoietin level.(ABSTRACT TRUNCATED AT 250 WORDS)     

The study of maternal and fetal plasma catecholamines levels during pregnancy and delivery.

BACKGROUND: To study maternal and fetal plasma levels of catecholamines (CA) during pregnancy and delivery, especially changes in CA levels during fetal distress and conditions of different modes of delivery. METHODS: Maternal and fetal plasma NE, E and DA levels were determined by high performance liquid chromatography (HPLC) for 16 non-pregnant women, 19 cases of early pregnancy, 17 cases of mid pregnancy, late pregnancy, spontaneous vaginal delivery and 53 cases of cesarean section. RESULTS: Plasma NE and DA levels decreased gradually with the advance of gestational weeks, and levels of plasma NE were significantly lower than those of non-pregnant women (P < 0.05). The levels of plasma CA in patients who had elective cesarean section were significantly lower than those who had vaginal delivery and emergency cesarean section (P < 0.01). However, CA levels of the cord artery in the vaginal delivery group were significantly higher than those in the cesarean section group (P < 0.01). CONCLUSION: Vaginal delivery is better than cesarean section for the newborn. If cesarean section is necessary, it is best for the newborn after onset of labor.     

Fetomaternal opioid levels and parturition

The present study evaluates the plasma level changes in beta-lipotropin and beta-endorphin in nine women at term throughout spontaneous labor, in ten pregnant women undergoing elective cesarean section in the absence of uterine contractions, and in ten women submitted to emergency cesarean section because of fetal distress occurring during labor. A basal plasma sample was taken before labor in the 39th week of pregnancy. Two subsequent samples were then obtained before and after parturition, together with umbilical cord samples at birth. beta-lipotropin and beta-endorphin were measured by radioimmunoassay after silicic acid plasma extraction and gel filtration. In cases of spontaneous labor, there was a progressive increase in opioid concentrations as labor progressed, the maximal values being observed after delivery. Cord values were similar to those observed in the mother, without showing any relationship to them. Pregnant women undergoing cesarean section in the absence of labor show constant beta-lipotropin and beta-endorphin concentrations both before and after fetal extraction, both values being significantly lower than those found at delivery after spontaneous labor. beta-Endorphin neonatal levels were significantly higher than in the respective mothers and were in the same range as those of infants born through vaginal delivery. In the third group (cesarean section performed at the first stage of labor), presurgical opioid levels were higher than in women at the same stage of spontaneous labor, whereas postextraction values showed a wide range, with mean values similar to those observed after spontaneous delivery.(ABSTRACT TRUNCATED AT 250 WORDS)     

不同分娩方式对低危孕产妇分娩结局及卫生经济学指标的影响

目的探讨不同分娩方式对低危孕产妇分娩结局及卫生经济学指标的影响。方法对2002年9月至2007年4月北京协和医院分娩的3751例孕37-41周^＋6的低危孕产妇的资料进行回顾性分析,按分娩的干预方式不同分为3组：择期引产组（包括药物及手术引产）501例、择期剖宫产组1634例和自然临产组1616例,分别对3组孕产妇的一般情况及住院费用以及分娩结局（产后出血、产褥病率、尿潴留、输血情况、切口愈合情况、产时副损伤）、新生儿Apgar评分情况等进行统计比较。结果（1）一般情况分析：自然临产组孕产妇住院天数（4．8d）与择期引产组（6．3d）及择期剖宫产组（6．3d）比较,差异有统计学意义（P〈0．01）;择期剖宫产组孕产妇住院费用（3472元）明显高于择期引产组（3201元）及自然临产组（2293元）,分别比较,差异有统计学意义（P〈0．01）,尤其是择期引产组中的剖宫产患者住院费用明显高于择期剖宫产组及自然临产组中的剖宫产患者,分别比较,差异均有统计学意义（P〈0．01）。（2）产时及产后并发症总发生率：孕产妇产时及产后并发症总发生率分别是择期引产组为12．4％、择期剖宫产组为0．9％,自然临产组为6．8％。（3）产后出血（≥500ml）发生率：择期引产组、择期剖宫产组和自然临产组分别为3．0％（15／501）、0．6％（9／1634）和1．2％（19／1616）,3组分别比较,差异有统计学意义（P〈0．01）。（4）尿潴留发生率：择期引产组、择期剖宫产组和自然临产组分别为4．6％（23／501）、0和3．3％（54／1616）,择期剖宫产组尿潴留发生率低于择期引产组与自然临产组（P〈0．01）,择期引产组与自然临产组比较,差异无统计学意义（P〉0．01）。（5）有无分娩中或产后输血：择期引产组、择期剖宫产组和自然临产组率孕产妇有输血者分别为2．0％（10／501）、0．1％（1／1634）和0．4％（6／1616）,3组分别比较,差异有统计学意义（P〈0．01）。（6）产时副损伤：择期引产组、择期剖宫产组和自然临产组产时副损伤发生率分别为0．6％（3／501）、0和0．4％（7／1616）,3组分别比较,择期剖宫产组低于其他两组（P〈0．01）,择期引产组与自然临产组比较,差异无统计学意义（P〉0．01）。（7）切口延期愈合：择期引产组、择期剖宫产组和自然临产组分别为0．8％（4／501）、0和0．2％（4／1616）,3组分别比较,差异有统计学意义（P〈0．01）。（8）产褥病率：3组间相互比较,差别无统计学意义（P〉0．01）。（9）新生儿窒息发生率：择期引产组、择期剖宫产组和自然临产组分别为1．2％（6／501）、0．1％（1／1634）和1．0％（17／1616）,择期剖宫产组与其他两组分别比较,差异均有统计学意义（P〈0．01）,择期引产组与自然临产组比较,差异无统计学意义（P〉0．01）。结论择期引产会增加孕产妇产后出血、分娩中或产后输血的机会,且没有降低产妇尿潴留、新生儿窒息的发生率;择期剖宫产是相对安全的分娩方式,对孕产妇分娩并发症的发生没有不良影响,但会明显增加住院费用。     

Interrelationships between maternal and cord prolactin, progesterone, estradiol, 13,14-dihydro-15-keto-prostaglandin F2alpha, and cord cortisol at delivery with respect to initiation of parturition

Estradiol, progesterone, prolactin, and 13,14-dihydro-15-keto prostaglandin F2alpha (PGFM) were measured in both maternal and cord venous blood obtained at the time of delivery in 24 maternal infant pairs evenly divided among six different physiologic groups. Progesterone and prolactin were significantly higher and estradiol was significantly lower in cord than in maternal blood. There were no significant differences between the groups for cortisol, estradiol, or progesterone in maternal or cord blood. A significant increase in prolactin was demonstrated in women receiving oxytocin for induction of labor. Both estradiol and PGFM were highly correlated between maternal and cord blood. PGFM was significantly higher in cesarean section patients in labor than in those not in labor in both the maternal and cord circulations. Among those delivered vaginally, PGFM tended to be higher in those in spontaneous labor than in those with induced labor. PGFM in induced labor was intermediate between spontaneous labor aptients delivered by cesarean section and those delivered vaginally. Duration of labor was negatively correlated with cord estradiol concentration. The physiologic significance of these findings is discussed.     

Calcium levels during the initiation of labor

OBJECTIVE: To investigate the physiological role of calcium in the labor process. STUDY DESIGN: Eighty-eight term healthy pregnant women who gave birth to normal healthy neonates participated in our study. We compared calcium levels between pregnant women who had normal delivery and those who underwent scheduled cesarean section. The control group consisted of pregnant women with gestation > or =37 weeks without contractions. The groups were compared with respect to calcium levels: (a) in maternal blood serum; (b) in blood serum of the neonates and mothers; and (c) in blood serum between neonates. RESULTS: Significantly higher calcium levels were found in the group of pregnant women who delivered vaginally compared to those who delivered by scheduled cesarean section and those of the control group. CONCLUSION: We assume that the increased calcium levels during the first stage of labor are involved with a possible role of calcium in the mechanism of initiation of labor.     

Modulation of hypothalamo-pituitary axis by stress during labor

OBJECTIVES: The present study is aimed to investigate the function of hypothalamo-pituitary-adrenal axis of women during late pregnancy and term labor. DESIGN: Levels of hormones were measured in blood of 34 women undergoing spontaneous labor and elective cesarean section, 2 days before and after delivery, and during labour. Additionally, blood from the umbilical vein and artery was also collected. MATERIALS AND METHODS: We have evaluated changes in corticotropin releasing hormone (CRH), adrenocorticotropin (ACTH) and dehydroepiandrosterone (DHEA) in vein blood of 34 subjects. The concentrations of hormones were measured by dint of RIA method. RESULTS: No significant correlation was found between hormone measurements and fetal outcome. CRH level in the umbilical vein was higher than in the umbilical artery, suggesting the placental origin of hormone. Prepartum CRH concentration was significantly higher in the group of spontaneously delivered patients. There were no correlations between CRH levels and ACTH and DHEA concentration in mother's blood plasma. In fetuses, higher prepartum CRH concentrations resulted in elevated levels of ACTH. No changes were found in DHEA concentration, in both mother and fetus. CONCLUSIONS: These results suggest that placental CRH may modulate a fetus's pituitary but not mother's. The observed high levels of this hormone play an important role mainly in preparation of mother and fetus for delivery.     

Oxidative stress as determined by glutathione (GSH) concentrations in venous cord blood in elective cesarean delivery versus uncomplicated vaginal delivery

OBJECTIVE: To determine whether neonates are subject to oxidative stress by the labor process and the mode of delivery by measuring glutathione (GSH) concentrations in umbilical cord venous blood. STUDY DESIGN: Forty-eight women with singleton term pregnancies were prospectively recruited and classified as follows: 26 women had a spontaneous uncomplicated vaginal delivery (VD), and 22 women had an elective cesarean delivery (CD). GSH concentration in umbilical venous blood samples was determined by a spectroscopic method. RESULTS: Umbilical cord venous blood GSH levels were significantly lower in the elective CD group than in the VD group (2.2 and 2.7 mM, respectively, P = 0.0003). There was a significantly negative correlation between cord blood pO(2) and GSH levels; however, the negative correlation was significantly higher in the elective CD group (P < 0.05). CONCLUSION: Neonates delivered by CD were exposed to a higher oxidative stress as determined by GSH levels compared to those who had an uncomplicated VD.     

Randomized management of the nonfrank breech presentation at term: a preliminary report

Cesarean section has become the standard management used by many clinicians for breech presentation in labor. Proof of the superiority of routine cesarean section has been largely circumstantial. Concern over rising cesarean section rates has led to renewed interest in possible alternatives. Protocols have been developed to select which patients may be allowed a trial of labor with frank breech presentation at term. We undertook a prospective clinical trial comparing elective cesarean section with a selective management protocol for the nonfrank breech presentation at term. One hundred five patients with nonfrank breech presentations at term in labor were studied. Seventy (67%) were randomized to a trial of labor and 35 (33%) to elective cesarean section. Of the patients allowed a trial of labor, 31 (44%) were delivered vaginally, and 39 (56%) required cesarean section. The largest single cause of a "failed" trial of labor was inadequate pelvic dimensions on x-ray pelvimetry (23 patients, 59%). Neonatal morbidity assessed by Apgar scores, cord gases, birth injury, and hospital stay was not different for those delivered vaginally or by cesarean section. Maternal morbidity in terms of febrile morbidity, blood transfusion, wound infections, and hospital stay was significantly greater among women delivered by cesarean section. Two of three neonatal deaths occurred in infants with major congenital anomalies. The third infant, apparently normal, died after vaginal delivery. Extensive evaluation suggests the death was attributable to inadequate resuscitation. We conclude that the use of a selective management protocol under controlled conditions is a reasonable alternative to elective cesarean section. Approximately one half of patients allowed a trial of labor may be expected to deliver vaginally with neonatal morbidity comparable to that seen with cesarean section.