Sherer D M, D'Amico M L, Cox C, Metlay L A, Woods J R
Department of Obstetrics and Gynecology, Strong Memorial Hospital, University of Rochester School of Medicine and Dentistry, New York.
Am J Perinatol. 1994 May;11(3):208-12. doi: 10.1055/s-2008-1040747.
Prospective analysis of 75 pairs of nonstress tests (NSTs) obtained simultaneously from both members of 35 twin gestations was performed to quantitatively assess the incidence of simultaneous periods of fetal heart rate (FHR) reactivity and nonreactivity of twins. Comparative analysis of the paired NSTs was used to compute rates of simultaneous fetal heart rate reactivity and nonreactivity. Statistical analysis involved comparison of weighted averages of these rates, using sequence lengths as weights. Weighted standard deviations were used to describe variability between sets of NSTs. Trend analysis was performed using weighted linear regression to calculate slopes for pairs of twins with three or more repeat NSTs. Groups of twins were compared by performing a variance stabilizing transformation on the appropriate rates, and using a two sample t test to compare the means of transformed data. Analysis of this data revealed that twins exhibited similar in utero fetal heart reactivity and nonreactivity as indicated by simultaneous electronic fetal monitoring during 79.90% +/- 1.62 (SD) of the time monitored. The incidence of periods of simultaneously reactive FHR and simultaneously nonreactive FHR were 11.79% +/- 1.02 and 68.10% +/- 2.17, respectively, irrespective of gestational age. These data confirm the hypothesis that periods of FHR reactivity and nonreactivity of twins are strongly associated with each other.
对35对双胎妊娠的两个胎儿同时进行的75次无应激试验（NST）进行前瞻性分析，以定量评估双胎胎儿心率（FHR）反应性和无反应性同时出现的发生率。采用配对NST的比较分析来计算同时出现的胎儿心率反应性和无反应性的发生率。统计分析包括以序列长度为权重，比较这些发生率的加权平均值。加权标准差用于描述NST组之间的变异性。对于有三次或更多次重复NST的双胎对，使用加权线性回归进行趋势分析以计算斜率。通过对适当的发生率进行方差稳定变换，并使用两样本t检验比较变换后数据的均值，对双胎组进行比较。对该数据的分析表明，在监测时间的79.90%±1.62（标准差）内，双胎在子宫内表现出相似的胎儿心率反应性和无反应性，这通过同步电子胎儿监护得以体现。无论孕周如何，FHR同时反应期和同时无反应期的发生率分别为11.79%±1.02和68.10%±2.17。这些数据证实了双胎FHR反应期和无反应期彼此密切相关的假设。
