Critical analysis of the validity of electronic fetal monitoring

Abstract

The validity of the diagnosis fetal distress based on electronic fetal monitoring (EFM) is low. It can be argued that the prediction of fetal distress may be influenced by the obstetric intervention, and a number of false-positive (FP) decisions are in fact cases of successful prevention of acidosis. The false-negative decisions (FN) may include cases in which an operative delivery was not performed, although the impaired fetal condition was correctly recognized. To estimated the magnitude of these effects, deliveries after 28 weeks of gestation, in which EFM was applied, were studied. The medical staff involved in these deliveries was asked to estimate the umbilical artery pH immediately before birth. After birth the pH was measured. Cases were classified as operative delivery for fetal distress or other. Fetal distress was supposes to be confirmed if the umbilical artery pH was less than or equal to 7.14. Pre-birth estimates of the pH were obtained in 393 cases. Of the 20 FP cases, 70% were real FP after considering the prebirth estimate; of the 35 FN cases, 89% were real FN. After correction for mistaken false results the sensitivity increased from 20.5% to 29.5% and the predictive value from 31.0% to 51.7%. Although validity and predictive values improve after correcting for the mistaken false results, their values are still unsatisfactorily low.

CTG-Überwachung ante- und intrapartual

“…Das relativiert ihre Aussagekraft für das Erkennen einer Asphyxie. Die Spezifität wird in der Literatur mit 40-50 angegeben, die Sensitivität mit 85 [6,7] …”

Rythme cardiaque fœtal pendant le travail : définitions et interprétation

“…Il n'y a pas d'étude randomisée comparant l'enregistrement du RCF et l'absence de surveillance du RCF [21] (NP5). La sensibilité du RCF continu pour le diagnostic d'issue néonatale défavorable est bonne et variable selon les anomalies prises en compte, mais sa valeur prédictive est médiocre avec un nombre important de faux positifs (plus de 50 %) [1,22,23] (NP2). Pour Steer et al [24], dans une étude prospective incluant 1219 naissances, la sensibilité du RCF en première phase du travail pour prédire l'acidose (pH Ao inférieur à 7,17) était de 47 % avec un taux de faux positifs de 14 % (NP2).…”

Evaluación Fetal Intraparto: Análisis Crítico De La Evidencia

“…Sin embargo, esta prueba diagnóstica dista mucho de ser el método ideal de evaluación fetal intraparto, y su ventaja real respecto de la tradicional auscultación intermitente de los LCF es pequeña y discutible. El monitoreo electrónico muestra una buena sensibilidad (~ 84%), pero una limitada especificidad (40-50%) en la predicción de hipoxia fetal intraparto (2). En otras palabras, un registro sugerente de bienestar fetal, nos da una "aceptable" tranquilidad; sin embargo, en al menos la mitad de los casos en que el registro es catalogado como "sospechoso" o "no tranquilizador", el feto también se encuentran en una situación de normalidad respiratorio-metabólica.…”