Department of Obstetrics and Gynaecology, Medical School, Demokritus University of Thrace, Str. Sarafi 3, 68100, Alexandroupolis, Greece.
Arch Gynecol Obstet. 2010 Feb;281(2):229-33. doi: 10.1007/s00404-009-1119-8. Epub 2009 May 20.
In this study, we tried to establish cut-off values for more than one parameters of computerized cardiotocography (c CTG) in the prediction of fetal distress during labor, using a group of pregnant women with low-risk pregnancies.
A retrospective study was performed. Data were collected from 167 patients for measurements of fetal heart rate (FHR) variables and perinatal outcome. Computerized CTG was performed with an Oxford Sonicaid monitor with connection to a 8000 system for CTG spontaneous analysis. The following c CTG variables were considered: FHR, number of accelerations, the presence and the number of episodes of high and low variation, the number of decelerations, short-term variation (STV), peaks of contractions (per hour) and fetal movements assessed by maternal perception (per hour). Computerized CTG recordings started not earlier than the beginning of week 38 of gestation. Immediately after delivery, blood sample was collected from umbilical artery for umbilical artery blood gas analysis (UBGA). The main UBGA parameter in cord umbilical artery that was considered for analysis was pH. pH values<7.25 were considered as suspicious for acidemia and pH values>or=7.25 as normal.
Women suspicious for fetal distress during labor presented significantly lower fetal movements (P=0.026), accelerations (P=0.018), variability (P<0.001), number of high episodes (P<0.001), higher values of FHR baseline (P<0.001) and low episodes (P<0.001). Only the number of decelerations did not differ significantly between the two groups (P=0.545). The cut-off points of 5.00 for STV and 3.00 for high episodes were determined to classify women with fetal distress, which yielded high sensitivities (34 and 52%) and specificities (96.6 and 94.9%), with positive predictive values of 81.0 and 81.3% and negative predictive values of 77.4 and 82.2%, respectively.
In conclusion, we believe that not only STV but also other components of the cCTG, mainly the presence and the number of episodes of high variation, are related to pregnancy's outcome as measured by an umbilical artery pH.
本研究旨在通过对低危妊娠孕妇的研究，为预测分娩时胎儿窘迫建立一个以上计算机胎心监护（c CTG）参数的截断值。
本研究采用回顾性研究方法，收集了 167 名孕妇的胎儿心率（FHR）变量和围产儿结局数据。使用 Oxford Sonicaid 监护仪和 8000 系统进行 CTG 自动分析，进行计算机 CTG 检查。考虑了以下 c CTG 变量：FHR、加速次数、高变异和低变异的出现和次数、减速次数、短期变异（STV）、宫缩高峰（每小时）和胎儿运动（由母体感知，每小时）。计算机 CTG 记录在妊娠 38 周前不开始。分娩后立即从脐动脉采集血样进行脐动脉血气分析（UBGA）。分析时考虑的脐动脉 UBGA 的主要参数是 pH 值。pH 值<7.25 被认为可疑酸中毒，pH 值≥7.25 为正常。
在分娩时疑似胎儿窘迫的孕妇中，胎儿运动（P=0.026）、加速（P=0.018）、变异性（P<0.001）、高变异次数（P<0.001）、FHR 基线值较高（P<0.001）和低变异次数（P<0.001）显著降低。两组间减速次数无显著差异（P=0.545）。STV 为 5.00 和高变异次数为 3.00 的截断点被确定为分类胎儿窘迫的妇女，其敏感性分别为 34%和 52%，特异性分别为 96.6%和 94.9%，阳性预测值分别为 81.0%和 81.3%，阴性预测值分别为 77.4%和 82.2%。
总之，我们认为，不仅是 STV，而且 cCTG 的其他组成部分，主要是高变异的出现和次数，与通过脐动脉 pH 值测量的妊娠结局有关。
