Guzman E R, Vintzileos A M, Martins M, Benito C, Houlihan C, Hanley M
Department of Obstetrics, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, USA.
Obstet Gynecol. 1996 Jun;87(6):969-74. doi: 10.1016/0029-7844(96)00020-8.
To determine the efficacy of individual fetal heart rate (FHR) indices, as determined by computer analysis of the FHR tracing, in detecting fetal acidemia at birth in growth-restricted fetuses.
The study population consisted of 38 growth-restricted fetuses at 26-37 weeks' gestation from pregnancies with abnormal uterine and/or umbilical artery Doppler velocimetry. The 1-hour FHR tracing was analyzed by computer within 4 hours of cesarean birth before the onset of labor. Umbilical artery cord blood was collected at birth, and pH was determined within 5 minutes of collection.
On linear regression, the duration of episodes of low variation in minutes (r = -0.77, r2 = 0.59) and short-term (r = 0.72, r2 = 0.52) and long-term (r = 0.69, r2 = 0.47) variation in milliseconds were significantly related to umbilical artery pH at birth, and more so than the number of accelerations of ten (r = 0.57, r2 = 0.32) and 15 (r = 0.38, r2 = 0.14) beats per minute. There were significant differences in computer measurements of FHR accelerations and variation between the umbilical artery pH categories of acidemia (pH less than 7.20), preacidemia (7.20-7.25), and nonacidemia (greater than 7.25). Stepwise regression revealed that episodes of low variation best described the model for predicting umbilical artery pH at birth (P < .001), with no improvement provided by the addition of other computer-analyzed FHR characteristics.
In this population of growth-restricted fetuses delivered by elective cesarean, the computer indices of duration of episodes of low variation and short-term and long-term variation were significantly associated with umbilical artery pH and predicted umbilical artery acidemia at birth.
通过对胎儿心率（FHR）描记图进行计算机分析，确定个体FHR指标在检测生长受限胎儿出生时是否存在胎儿酸血症方面的有效性。
研究对象包括38例妊娠26 - 37周的生长受限胎儿，其妊娠伴有子宫和/或脐动脉多普勒血流速度测定异常。剖宫产出生前4小时内（未临产时），由计算机对1小时的FHR描记图进行分析。出生时采集脐动脉血，采集后5分钟内测定pH值。
线性回归分析显示，低变异持续时间（分钟）（r = -0.77，r² = 0.59）、短期变异（r = 0.72，r² = 0.52）和长期变异（r = 0.69，r² = 0.47）（毫秒）与出生时脐动脉pH值显著相关，且比每分钟10次（r = 0.57，r² = 0.32）和15次（r = 0.38，r² = 0.14）加速的次数相关性更强。在酸血症（pH小于7.20）、酸血症前期（7.20 - 7.25）和非酸血症（大于7.25）的脐动脉pH值类别之间，FHR加速和变异的计算机测量值存在显著差异。逐步回归分析显示，低变异持续时间最能描述预测出生时脐动脉pH值的模型（P < 0.001），添加其他计算机分析的FHR特征并不能改善该模型。
在这群择期剖宫产分娩的生长受限胎儿中，低变异持续时间以及短期和长期变异的计算机指标与脐动脉pH值显著相关，并可预测出生时的脐动脉酸血症。
