Diagnosis and Management of a Persistently Nonreassuring FHR Pattern
A reassuring FHR pattern (Category I) may include a nor-mal baseline rate, moderate FHR variability, persistence of accelerations, and absence of decelerations. Patterns believed to be predictive of current or impending fetal as-phyxia (Category III) include recurrent late decelerations, recurrent severe variable decelerations, or sustained brady-cardia with absent FHR variability. A nonreassuring pattern (Category II) is one that falls between these two extremes.
In the presence of a nonreassuring FHR pattern, the etiology should be determined, if possible, and an attempt should be made to correct the pattern by addressing the primary problem. If the pattern persists, initial measures include changing the lateral position to the left lateral po-sition, administering oxygen, correcting maternal hypo-tension, and discontinuing oxytocin, if appropriate. Where the pattern does not respond to change in position or oxy-genation, the use of tocolytic agents has been suggested to abolish uterine contractions and prevent umbilical cord compression. Uterine hyperstimulation can be identified by evaluating uterine contraction frequency and duration and can be treated with beta-adrenergic drugs. Amnio-infusion may also be used to prevent umbilical cord com-pressions. Awaiting vaginal delivery is appropriate if it has beendetermined that delivery is imminent. If it is not, and there is evidence of progressive fetal hypoxia and acidosis, cesarean delivery is warranted.