L'INTERPRETAZIONE DEL MONITORAGGIO CARDIOTOGRAFICO IN TRAVAGLIO DI PARTO: CLASSIFICAZIONI A CONFRONTO NELL'IDENTIFICAZIONE DEL DISTRESS FETALE.

Title Comparison of two classification systems for interpreting electronic fetal monitoring in predicting fetal distress Abstract Background. With the diffusion of the cardiotocography (CTG) many attempts have been made to correlate the traces with the neonatal outcome with the aim to promptly predict any neonatal distress. However, no definitive agreement exists on its clinical role. The aim of this study was the analysis in a case-control fashion of a series of CTG traces in regards to their capability to detect corresponding values of pH. Methods. A series of 71 cases of operative deliveries for neonatal distress were compared with a series of 68 controls of operative deliveries performed not for neonatal distress. A senior and a junior consultant retrospectively analyzed the CTG traces based on two classifications, the Royal College of Obstetricians and Gynecologists (RCOG), and the American College of Obstetricians and Gynecologists (ACOG). Sensitivity, specificity, positive and negative predictive values were calculated. The accuracy of these classifications to predict a pH≤7 was tested using the receiver-operating characteristic (ROC) curves. Agreement between the two consultants and the two classifications was calculated with the Cohen’s kappa test. Univariate and multivariate analyses of prognostic factors were also performed. Results. Considering pH ≤7 the sensitivity, specificity, positive and negative predictive values were 78%, 73%, 25%, 97% and 78%, 87%, 47%, 96% for RCOG and ACOG respectively. At the ROC curves ACOG had a slight better AUC (0,684 versus 0,649). A fair to good agreement resulted between the two consultants even if in control group the agreement was better for two classification (Weighted k value case group RCOG 0.59/ACOG 0.49; control group Weighted k value RCOG 0.66 /ACOG 0.62). It was a low agreement between two consultants to give the same classification. Major experience of senior-consultant showed better results in term of providing pH at birth. At univariate analysis no specific factors were found to be associated with neonatal distress. Conclusions. The study demonstrate that the two classification used to evaluate EFM in labor have a good sensibility in predicting fetal distress even if the low prevalence of the target condition. Intra/inter-operator disagreement is an important limiting factor.