Reliability of Cardiotocography in the Assessment of Fetal Heart Rate Patterns

Background/Objectives:The classification of fetal heart rate (FHR) patterns is performed visually by obstetricians and gynecologists, which sometimes results in problematic discrepancies between assessments. Cardiotocography (CTG), which automatically performs pattern classifications using a computer, has been introduced recently to address this problem. The purpose of this study was to examine the reliability of assessments by obstetricians and by CTG (Trium), as well as identify factors that contribute to differences in assessments. Methods: Obstetricians used the FHR guidelines to perform pattern classifications according to baseline, variability, and deceleration of the FHR. Inter-rater reliability, Trium-reliability, and intra-rater reliability were evaluated using Kappa scores. Results: There was a high degree of agreement among obstetricians involved in the assessment of FHR patterns. However, deceleration of the FHR was associated with disagreement with the Trium CTG automatic assessment system, and there were clear differences in assessments between mild variable and mild late, as well as severe variable and severe late patterns. Conclusions: These findings suggest that the deceleration category program of Trium CTG could be improved to obtain results closer to those of visual assessments.