Fetal Heart Rate Tracing Category II: A Broad Category in Need of Stratification

Abstract

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.