對第一胎懷孕婦女自然生產之胎兒做臍血氧分析

中文摘要 對第一胎懷孕婦女自然生產之胎兒做臍血氧分析 研究目的 : 第一胎健康婦女自然足月生產，探討其接受生產介入(obstetric intervention) 包括 : (1) 接受會陰切開術 (2) 使用無痛分娩 (3)使用器械式生產(vacuum) (4) 催生劑使用，和過長的第二產程生產與過重的孕婦體質比(Body mass index)，比較在這些情況下，胎兒臍血血氧濃度差異，以預測出生胎兒的健康狀態(Fetal well-being)。 研究設計及方法 : 本實驗為前瞻性描述型之研究 (Prospective Descriptive Study) ，自2003年8月至2004年2月之間， 對象為40位在中山醫學大學附設醫院之第一胎自然足月陰道生產的健康婦女，收集其分娩無先天異常之胎兒臍血，研究分析臍血血氧情況。臍帶血的收集，胎兒分娩後，立即以臍帶夾( cord clamps)，將一段的胎兒臍帶獨立出來，分別以3cc. 事先用以heparin浸潤的空針，收集臍動脈血和臍靜脈血(最少1cc)置入冰浴中，並且在胎兒分娩後的30分鐘內送達實驗室做臍血氧分析。 利用統計假說檢定(Statistical hypothesis test)來分析處理: H0: 接受生產介入的胎兒臍帶血pH值與未接受生產介入的胎兒臍帶血pH值相同。 HA: 接受生產介入的胎兒臍帶血pH值與未接受生產介入的胎兒臍帶血pH值不同。 使用SPSS進行統計分析： 1. Logistic regression analysis was used for multivariate analysis and odds ratios (OR) with their 95% confidence intervals were estimated. 2. 類別資料: To compare categorical variables used the Chi-square test 3. 獨立連續性的資料: To compare independent continuous variables used the t-test. 4. 三組平均數的差異:Repeated ANOVA 分析之。 統計上的顯著差異(Statistically significant)為p-value<0.05。 研究結果 : 40位初產婦(nullipara)、單胎(singleton)懷孕的婦女：其平均年齡為27歲 ( range, 15-37; SD, 5.17)，懷孕的平均週數是38.5週 ( range, 36-41; SD, 1.33)，孕婦平均身高為158.8cm ( range, 152-171; SD,4.70)，平均體重為63.7kg ( range, 52-76; SD, 5.88)，孕婦平均BMI為25.3 ( range, 21-32; SD, 2.51)，胎兒在第二產程分娩的平均時間為30.9分鐘( range, 4-85; SD, 20.6)，胎兒的平均體重是2947公克(range, 2210-3720; SD, 351.8)。 在這40個分娩的胎兒其臍帶血氧分析，臍帶動脈血的平均pH值7.26，其標準差為0.072；血中二氧化碳平均值為 52.9mmHg，其標準差為9.24；HCO3平均值為 23.2 mEq/l，其標準差為9.24；Base Deficit平均值為 -4.38，其標準差為3.04。 臍帶靜脈血的平均pH值7.31，其標準差為0.071；血中二氧化碳平均值為 41.7mmHg，其標準差為7.95；HCO3平均值為 20.6 mEq/l，其標準差為2.89；Base Deficit平均值為 -5.42，其標準差為3.25。 胎兒臍帶動脈血分析的結果，以fetal acidosis, pH小於7.20。利用Logistic regression 進行類別變數統計分析，得到以下的結果： 生產介入的因素與fetal acidosis(pH<7.20)之相關性： Uni-variate Logistic regression分析時發現，會陰部切開 (Odds Ratio, 1.22 ; 95% Confidence Intervals, 0.21-7.11)，催生劑使用(Odds Ratio, 1.05 ;95% Confidence Interval, 0.22-5.08)，真空式生產(Odds Ratio, 3.59 ;95% Confidence Interval, 0.77-16.8)，無痛分娩(Odds Ratio, 2.67 ; 95% Confidence Interval, 0.37-19.2)。 其他考慮因素與fetal acidosis之相關性： 第二產程時間 (≧30 min) (Odds Ratio, 1.73 ;95% Confidence Interval,0.39-7.72)，孕婦Body mass index(≧25) (Odds Ratio, 1.88; 95% Confidence Interval,0.39-8.88)，上述之各項變數與fetal acidosis之間無統計學之意義。 利用Uni-variate Logistic regression分析發現，會陰部切開 (Odds Ratio, 1.096 ;95% Confidence Intervals, 0.07-16.6)，催生劑使用(Odds Ratio, 16.48 ;95% Confidence Interval, 1.21-226.1)，真空式生產 (Odds Ratio, 10.76 ;95% Confidence Interval, 1.025-112.9)，無痛分娩 (Odds Ratio, 0.074 ; 95% Confidence Interval, 0.003-2.09)，第二產程時間 (≧30 min) (Odds Ratio, 0.93 ;95% Confidence Interval,0.155-5.58)，孕婦Body mass index(≧25) (Odds Ratio, 1.71; 95% Confidence Interval,0.25-11.6)。 當以Multi-variate Logistic regression分析時，上述之各項變數與fetal acidosis之間催生劑使用(Odds Ratio, 16.48 ;95% Confidence Interval, 1.21-226.1) 和真空式生產 (Odds Ratio, 10.76 ;95% Confidence Interval, 1.025-112.9)有統計學之意義。 實驗發現無上述之任何生產介入者 n=8 ，其臍帶動脈血平均pH為7.288，標準差為0.039；生產介入者 n=32，其臍帶動脈血平均pH為7.253，標準差為0.076。利用t test，比較兩組平均數得到p=0.075，無統計學意義。 臍帶血氧情況在第5分鐘、第10分鐘 和第15分鐘之比較利用Repeated ANOVA測量三次不同時間所得到的氣體分析值之平均數，發現無統計學上之差異(no significant difference)。 研究結論 : 所有40位出生胎兒皆無出現神經異常變化，也皆無胎兒死亡 ( No mortality and no morbidity)。 對第一胎自然足月生產的健康婦女而言，以pH值來評估胎兒的酸血(fetal acidosis)情狀，其接受生產介入(obstetric intervention) 包括 : (1) 接受會陰切開術 (2) 使用無痛分娩 (3)使用器械式生產(vacuum) (4) 催生劑使用，以及過長的第二產程生產(≧30分鐘)和過重的孕婦體質比(BMI≧25)，這些的變因與胎兒的酸血症(fetal acidosis, pH< 7.20)，當以 Uni-variate Logistic regression分析時，上述之各項變數與fetal acidosis之間無統計學之意義。。當以Multi-variate Logistic regression分析時，上述之各項變數與fetal acidosis之間催生劑使用(Odds Ratio, 16.48 ;95% Confidence Interval, 1.21-226.1) 和真空式生產 (Odds Ratio, 10.76 ;95% Confidence Interval, 1.025-112.9)有統計學之意義。

Abstract Umbilical cord Blood Analysis for Women at First Spontaneous Vaginal Delivery OBJECTIVE: To analyze the gas values of the umbilical cord blood in the first vaginal delivered babies and to verify those differences of the effects associated with obstetrical interventions including delivery mode, episiotomy, epidural anesthesia and uterine augmentation , and the other effects including prolonged duration of the second stage and excess maternal body mass index. DESIGN: A prospective descriptive study of umbilical cord artery and vein blood gas results. METHODS: During the period from August 2003 and February 2004 in the Hospital of Chung-Shan Medical University, umbilical cord blood gas results were analyzed of forty term-newborns delivered vaginally from forty health-nulliparous women. RESULTS: The mean age of 40 nulliparous woman with singleton was 27 year-old (range 15-37,SD 5.17). The mean of maternal BMI was 25.3 (range,21-32; SD, 2.51) The mean duration of second stage was 30.9 min (range 4-85 ,SD 20.6) The mean birth fetal weight was 2947 gm (range 2210-3720, SD 351.8).Thirty-three of forty babies was umbilical artery levels of pH≧7.20, and nine of forty newborns was pH<7.20. Using Uni-variate logistic regression for those factors, fetal acidosis had no significant associations with those obstetric interventions which were episiotomy use (OR, 1.22 ; 95%CI, 0.21-7.11), oxytocin augmentation (OR, 1.05 ;95% CI, 0.22-5.08), vacuum extraction (OR, 3.59 ;95% CI, 0.77-16.8) and epidural anesthesia (OR, 2.67 ; 95% CI, 0.37-19.2) , and the other concerned factors which were the duration of second stage (≧30 min) (OR, 1.73 ;95% CI,0.39-7.72) and maternal Body mass index(≧25) (OR, 1.88; 95% CI,0.39-8.88). After controlling the confounding factors with multi-variate logistic regression, episiotomy use (Odds Ratio, 1.096 ;95% Confidence Intervals, 0.07-16.6), oxytocin augmentation (Odds Ratio, 16.48 ;95% Confidence Interval, 1.21-226.1), vacuum extraction (Odds Ratio, 10.76 ;95% Confidence Interval, 1.025-112.9), epidural anesthesia (Odds Ratio, 0.074 ; 95% Confidence Interval, 0.003-2.09) , the duration of second stage (≧30 min) (Odds Ratio, 0.93 ;95% Confidence Interval,0.155-5.58) and maternal Body mass index(≧25) (Odds Ratio, 1.71; 95% Confidence Interval,0.25-11.6). Fetal acidosis had significant associations fetal acidosis with oxytocin augmentation (Odds Ratio, 16.48 ;95% Confidence Interval, 1.21-226.1) and vacuum extraction (Odds Ratio, 10.76 ;95% Confidence Interval, 1.025-112.9) The umbilical artery levels of pH of the obstetric intervention group (n=32) and non-obstetric intervention group (n=8) were 7.25 (SD, 0.076) vs 7.29 (SD, 0.039) which also had no statistic significancy ( p=0.075). CONCLUSION: Forty newborns had no neurologic defects at birth and no mortality and no morbidity during postnatal care. By measuring the umbilical blood pH, the obstetric interventions including episiotomy use, oxytocin augmentation, vacuum extraction and epidural anesthesia had no significant association with fetal acidosis (pH<7.20) when using uni-variate logistic regression. Fetal acidosis had significant associations fetal acidosis with oxytocin augmentation (Odds Ratio, 16.48 ;95% Confidence Interval, 1.21-226.1) and vacuum extraction (Odds Ratio, 10.76 ;95% Confidence Interval, 1.025-112.9) when using multi-variate logistic regression. The group of obstetric interventions and the group of non-obstetric interventions also had no significant difference with fetal acidosis at birth in nulliparous women.