Department of Obstetrics and Gynecology, New York Medical College, Metropolitan Hospital, NYC Health+Hospitals, New York, NY.
Wayne State University School of Medicine, Detroit, MI.
Neoreviews. 2021 Feb;22(2):e88-e94. doi: 10.1542/neo.22-2-e88.
Fetal heart rate (FHR) tracings are classified into 3 categories per the National Institute of Child Health and Human Development guidelines. There exists broad consensus on the recognition and management of categories I and III. However, a category II FHR tracing is considered "indeterminate" and cannot be classified as either reassuring or non-reassuring. Absence of variability and high frequency and increased depth of decelerations are the key determining factors that make a category II tracing non-reassuring and are associated with fetal metabolic acidosis. Periodic category II tracing is present in the majority of normal laboring patients. In the setting of a category II tracing, an initial attempt should be made for in utero resuscitation of the fetus. If the tracing fails to improve over a period of 1 to 2 hours, or the fetal tracing gradually deteriorates, a decision should be made for operative vaginal or cesarean delivery. Category II tracing management algorithms can aid in decision-making in this uncertain clinical scenario. Team training and simulation may improve team performance and have a positive impact on neonatal outcomes.
胎儿心率（FHR）描记图可根据美国国立儿童健康与人类发育研究所的指南分为 3 类。对于 I 类和 III 类的识别和管理，已经达成广泛共识。然而，II 类 FHR 描记图被认为是“不确定的”，不能归类为令人安心或不令人安心。缺乏变异、高频和减速加深是使 II 类描记图不令人安心的关键决定因素，与胎儿代谢性酸中毒有关。大多数正常分娩的患者都会出现周期性的 II 类描记图。在 II 类描记图的情况下，应首先尝试对胎儿进行宫内复苏。如果在 1 到 2 小时内描记图没有改善，或者胎儿描记图逐渐恶化，应决定进行阴道助产或剖宫产。II 类描记图管理算法可帮助在这种不确定的临床情况下做出决策。团队培训和模拟可以提高团队绩效，并对新生儿结局产生积极影响。
