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To the Editors:Crosby’s comments on our article reviewing the future of fetal heart rate (FHR) monitoring bring out an extremely important point regarding FHR management. In the example he uses, that of late decelerations with undetectable FHR variability, we agree that intervention at that late stage may not avoid asphyxial fetal damage. However, the crucial management point is as follows: Can one identify a FHR pattern that will evolve into one significant of “deep central asphyxia”? It is our belief (unencumbered as yet by incontrovertible data) that the progressive evolution of patterns is sufficiently well established that we can make such projections in many cases. The central dogma states that decreasing FHR variability from asphyxia during labor will virtually always be associated with late or variable decelerations or with bradycardia. Except for catastrophic events (eg, complete abruptio placentae, prolapsed cord, or extrusion of the fetus through a uterine rupture), this evolution of decelerations or bradycardia with retained FHR variability, gradual deepening of the decelerations, reduction of variability, and finally absence of FHR variability generally occurs through a period long enough to allow intervention, approximately an hour. This schema is supported by evidence in the literature. Admittedly, the evidence is mostly grade III, but we believe that it is sufficiently strong to construct a management protocol for subsequent randomized testing, as alluded to by Crosby.6/8/111299 To the Editors:Crosby’s comments on our article reviewing the future of fetal heart rate (FHR) monitoring bring out an extremely important point regarding FHR management. In the example he uses, that of late decelerations with undetectable FHR variability, we agree that intervention at that late stage may not avoid asphyxial fetal damage. However, the crucial management point is as follows: Can one identify a FHR pattern that will evolve into one significant of “deep central asphyxia”? It is our belief (unencumbered as yet by incontrovertible data) that the progressive evolution of patterns is sufficiently well established that we can make such projections in many cases. The central dogma states that decreasing FHR variability from asphyxia during labor will virtually always be associated with late or variable decelerations or with bradycardia. Except for catastrophic events (eg, complete abruptio placentae, prolapsed cord, or extrusion of the fetus through a uterine rupture), this evolution of decelerations or bradycardia with retained FHR variability, gradual deepening of the decelerations, reduction of variability, and finally absence of FHR variability generally occurs through a period long enough to allow intervention, approximately an hour. This schema is supported by evidence in the literature. Admittedly, the evidence is mostly grade III, but we believe that it is sufficiently strong to construct a management protocol for subsequent randomized testing, as alluded to by Crosby.6/8/111299 Crosby’s comments on our article reviewing the future of fetal heart rate (FHR) monitoring bring out an extremely important point regarding FHR management. In the example he uses, that of late decelerations with undetectable FHR variability, we agree that intervention at that late stage may not avoid asphyxial fetal damage. However, the crucial management point is as follows: Can one identify a FHR pattern that will evolve into one significant of “deep central asphyxia”? It is our belief (unencumbered as yet by incontrovertible data) that the progressive evolution of patterns is sufficiently well established that we can make such projections in many cases. The central dogma states that decreasing FHR variability from asphyxia during labor will virtually always be associated with late or variable decelerations or with bradycardia. Except for catastrophic events (eg, complete abruptio placentae, prolapsed cord, or extrusion of the fetus through a uterine rupture), this evolution of decelerations or bradycardia with retained FHR variability, gradual deepening of the decelerations, reduction of variability, and finally absence of FHR variability generally occurs through a period long enough to allow intervention, approximately an hour. This schema is supported by evidence in the literature. Admittedly, the evidence is mostly grade III, but we believe that it is sufficiently strong to construct a management protocol for subsequent randomized testing, as alluded to by Crosby. 6/8/111299