Interobserver agreement in analysis of cardiotocograms recorded during trial of labor after cesarean

Abstract

Introduction: To examine interobserver agreement in intrapartum cardiotocography (CTG) classification in women undergoing trial of labor after a cesarean section (TOLAC) at term with or without complete uterine rupture.

Materials and methods: Nineteen blinded and independent Danish obstetricians assessed CTG tracings from 47 women (174 individual pages) with a complete uterine rupture during TOLAC and 37 women (133 individual pages) with no uterine rupture during TOLAC. Individual pages with CTG tracings lasting at least 20 min were evaluated by three different assessors and counted as an individual case. The tracings were analyzed according to the modified version of the Federation of Gynaecology and Obstetrics (FIGO) guidelines elaborated for the use of STAN (ST-analysis). Occurrence of defined abnormalities was recorded and the tracings were classified as normal, suspicious, pathological, or preterminal. The interobserver agreement was evaluated using Fleiss’ kappa.

Results: Agreement on classification of a preterminal CTG was almost perfect. The interobserver agreement on normal, suspicious or pathological CTG was moderate to substantial. Regarding the presence of severe variable decelerations, the agreement was moderate. No statistical difference was found in the interobserver agreement between classification of tracings from women undergoing TOLAC with and without complete uterine rupture.

Conclusions: The interobserver agreement on classification of CTG tracings from high-risk deliveries during TOLAC is best for assessment of a preterminal CTG and the poorest for the identification of severe variable decelerations.

Keywords:

• Cardiotocography
• Fleiss’ kappa
• interobserver agreement
• trial of labor after cesarean (TOLAC)
• uterine rupture

Acknowledgments

The authors thank the Danish cardiotocography (CTG) monitoring during VBAC study group for assessment of the cardiotocograms. The group was composed by Lise Lotte Torvin Andersen, Dept. of Obstetrics and Gynecology, Odense Hospital. Charlotte Brix Andersson, Department of Obstetrics and Gynecology, Aalborg Hospital. Anders Atke, Department of Obstetrics and Gynecology, Herlev Hospital. Diana B.B. Bach, Dept. of Obstetrics and Gynecology, Hvidovre Hospital. Thomas Bergholt, Dept. of Obstetrics and Gynecology, Rigshospitalet. Nina SP Colov, Dept. of Obstetrics and Gynecology, Rigshospitalet. Morten Hedegaard, Dept. of Obstetrics and Gynecology, Rigshospitalet. Lisbeth Jønsson, Dept. of Obstetrics and Gynecology, Naestved Hospital. Rikke Bek Helmig, Dept. of Obstetrics and Gynecology, Aarhus Hospital. Lone Hvidman, Dept. of Obstetrics and Gynecology, Aarhus Hospital. Carsten Lenstrup, Dept. of Obstetrics and Gynecology, Hvidovre Hospital. Thea Lousen, Dept. of Obstetrics and Gynecology, Roskilde Hospital. Jens Lyndrup, Dept. of Obstetrics and Gynecology, Hvidovre Hospital. Margrethe Møller, Dept. of Obstetrics and Gynecology, Aalborg Hospital. Heidi Sharif, Dept. of Obstetrics and Gynecology, Naestved Hospital. Tom Weber, Dept. of Obstetrics and Gynecology, Hvidovre Hospital. Hanne Brix Westergaard, Dept. of Obstetrics and Gynecology, Hilleroed Hospital. Birgitte Østberg, Dept. of Obstetrics and Gynecology, Naestved Hospital.

Disclosure statement

No potential conflict of interest was reported by the authors.