Westgate Jenny A, Wibbens Bert, Bennet Laura, Wassink Guido, Parer Julian T, Gunn Alistair J
Department of Obstetrics and Gynaecology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, NZ.
Am J Obstet Gynecol. 2007 Sep;197(3):236.e1-11. doi: 10.1016/j.ajog.2007.03.063.
One of the most distinctive features of fetal heart rate recordings in labor is the deceleration. In clinical practice, there has been much confusion about the types of decelerations and their significance. In the present review, we examined uteroplacental perfusion in labor, describe the pathophysiologic condition of decelerations, and explain some of the reasons behind the confusion about the terminology. We summarize recent studies that systematically have dissected the features of variable decelerations that may help to identify developing fetal compromise, such as the slope of the deceleration, overshoot, and variability changes. Although no pattern of repeated deep decelerations is necessarily benign, fetuses with normal placental reserve can compensate fully, even for frequent deep but brief decelerations, for surprisingly prolonged intervals before the development of profound acidosis and hypotension. This tolerance reflects the remarkable ability of the fetus to adapt to repeated hypoxia. We propose that, rather than focus on descriptive labels, clinicians should be trained to understand the physiologic mechanisms of fetal heart rate decelerations and the patterns of fetal heart rate change that indicate progressive loss of fetal compensation.
产程中胎儿心率记录最显著的特征之一是减速。在临床实践中，对于减速的类型及其意义存在诸多混淆。在本综述中，我们研究了产程中的子宫胎盘灌注，描述了减速的病理生理状况，并解释了术语混淆背后的一些原因。我们总结了近期系统剖析可变减速特征的研究，这些特征可能有助于识别正在发展的胎儿窘迫，如减速的斜率、过冲和变异性变化。尽管反复出现的深度减速模式不一定是良性的，但胎盘储备正常的胎儿即使频繁出现深度但短暂的减速，在发生严重酸中毒和低血压之前，也能在令人惊讶的长时间内充分代偿。这种耐受性反映了胎儿适应反复缺氧的非凡能力。我们建议，临床医生不应专注于描述性标签，而应接受培训，以了解胎儿心率减速的生理机制以及表明胎儿代偿能力逐渐丧失的胎儿心率变化模式。
