A new modality in nonstress testing: evaluation of beat-to-beat fetal heart rate variability.
Fetal monitoring equipment that provided accurate external measurement of the interval between each fetal heartbeat permitted the evaluation of beat-to-beat fetal heart rate (FHR) variability as part of routine nonstress testing. Nonstress tests (NSTs) were performed on 350 high-risk patients over a 12-month period. The beat-to-beat FHR variability and the reactivity of the last NST within 7 days of labor were analyzed in relation to the appearance of fetal distress during labor as indicated by late decelerations. Beat-to-beat FHR variability combined with nonstress testing was more predictive of subsequent fetal distress than nonstress testing alone. In all instances, complete loss of beat-to-beat FHR was followed by fetal distress during labor. Fetal distress was present in only 39% of labors following nonreactive NSTs. The inclusion of beat-to-beat FHR variability in nonstress testing can significantly aid in the detection of fetal compromise.
D005260:Female; D005316:Fetal Distress / Q000175:diagnosis / Q000503:physiopathology*; D005318:Fetal Heart / Q000502:physiology*; D005323:Fetal Monitoring / Q000379:methods; D006339:Heart Rate; D006801:Humans; D009068:Movement; D011247:Pregnancy; D011248:Pregnancy Complications; D012306:Risk