Petrikovsky B M, Vintzileos A M, Nochimson D J
Department of Obstetrics and Gynecology, University of Connecticut Health Center, Farmington 06032.
Am J Perinatol. 1989 Jul;6(3):289-91. doi: 10.1055/s-2007-999595.
Fifty-four intrapartum fetal heart rate (FHR) tracing were subjected to retrospective analysis of the presence, length, and frequency of cyclic changes in long-term variability (cyclicity). All patients had spontaneous uncomplicated labor and received no narcotics or analgesics. The following cycles were identified according the difference in long-term variability in terms of amplitude range: cycle A, 0 to 2.5 beats/min; cycle B, 3 to 5 beats/min; cycle C, 6 to 10 beats/min; and cycle D, 11 to 20 beats/min. The frequency and length of FHR cycles was established in the latent, active phases and second stage of labor. Periods of diminished variability should be followed by fetal acid-base assessment only if their duration exceeds the established norms.
对54份产时胎儿心率（FHR）描记图进行回顾性分析，以确定长期变异性（周期性）变化的存在、时长和频率。所有患者均为自然分娩且无并发症，未使用麻醉剂或镇痛药。根据长期变异性在幅度范围上的差异，确定了以下周期：A周期，0至2.5次/分钟；B周期，3至5次/分钟；C周期，6至10次/分钟；D周期，11至20次/分钟。在潜伏期、活跃期和第二产程确定FHR周期的频率和时长。只有当变异性降低的持续时间超过既定标准时，才应在其后进行胎儿酸碱评估。
