Inter- and intra-observer agreement of non-reassuring cardiotocography analysis and subsequent clinical management

Abstract

Objective: To quantify inter- and intra-observer agreement of non-reassuring intrapartum cardiotocography (CTG) patterns and subsequent clinical management.

Design: Methodological study.

Setting: University Medical Center.

Population: CTG patterns of 79 women beyond 37 weeks of gestation with a singleton fetus in vertex position in first stage of labor in whom fetal blood sampling (FBS) had been performed.

Methods: Nine observers assessed CTG patterns, which were formerly clinically classified as non-reassuring and indicative for FBS, according to the guidelines of the International Federation of Gynecology and Obstetrics modified for ST analysis. They also proposed clinical management strategies without and with insight into clinical parameters. Weighted kappa values (κw ) and proportions of agreement (Pa ) were calculated.

Main outcome measures: Agreement on CTG classification and clinical management.

Results: Inter-observer agreement on CTG classification and on clinical management were poor for most observer categories (κw range 0.31-0.50 and 0.20-0.45, respectively). Observers agreed best on abnormal CTG patterns (Pa range 0.28-0.36) and on the clinical management option "continue monitoring" (Pa range 0.32-0.40). Intra-observer agreement was fair to good for most observers (κw 0.33-0.70). Insight into clinical parameters resulted in similar inter- and intra-observer agreement.

Conclusions: There was poor inter-observer agreement and fair to good intra-observer agreement on classification and clinical management of intrapartum CTG patterns, which had been classified as non-reassuring and indicative for FBS during birth.

Keywords: Fetal blood; cardiotocography; fetal monitoring; inter- and intra-observer agreement; labor and delivery.