Laplanche B, Brandel E, Magnin G
Service de Gynécologie-Obstétrique, Hôpital Jean-Bernard, CHRU, Poitiers.
J Gynecol Obstet Biol Reprod (Paris). 1996;25(6):612-6.
Determine whether the pH of fetal scalp blood gives a better evaluation of fetal status and whether cesarean section can be avoided in case of abnormal fetal heart rate.
For last 100 patients in which the scalp blood was sampled, scalp pH was compared with cord pH, Agpar score at birth and immediate neonatal outcome.
Among the 100 cases, there were 75 vaginal deliveries. There was a good correlation between scalp pH, umbilical artery pH and the 5-min Apgar score. The specificity of scalp pH > or = 7.25 to identify infants with an umbilical artery pH > or = 7.25 and 5-min Apgar score > or = 7 was 98.5 and 90.7% respectively; the corresponding negative predictive values were 70.3 and 96.7%. Immediate neonatal outcome was favorable for all the vaginal deliveries (n = 75) even though fetal heart rate was abnormal. Scalp pH presumably helped avoid unnecessary cesareans in 60 cases as in 15 case delivery occurred within 30 min or less after fetal scalp blood sampling.
Scalp blood sampling for determination of pH is questioned and other methods for evaluating fetal status are being examined. But until these methods can be validated, scalp pH provides a means of avoided some unnecessary cesareans in cases where the fetal heart rate is difficult to analyse.
确定胎儿头皮血pH值是否能更好地评估胎儿状况，以及在胎儿心率异常时是否可避免剖宫产。
对最近100例采集头皮血的患者，将头皮pH值与脐血pH值、出生时的阿氏评分及新生儿即刻结局进行比较。
100例中，有75例经阴道分娩。头皮pH值、脐动脉pH值与5分钟阿氏评分之间存在良好相关性。头皮pH值≥7.25用于识别脐动脉pH值≥7.25且5分钟阿氏评分≥7的婴儿的特异性分别为98.5%和90.7%；相应的阴性预测值分别为70.3%和96.7%。即使胎儿心率异常，所有经阴道分娩的75例新生儿即刻结局均良好。在60例中，头皮pH值可能有助于避免不必要的剖宫产，因为在15例中，胎儿头皮血采样后30分钟或更短时间内即分娩。
用于测定pH值的头皮血采样受到质疑，正在研究评估胎儿状况的其他方法。但在这些方法得到验证之前，头皮pH值为在胎儿心率难以分析的情况下避免一些不必要的剖宫产提供了一种方法。
