Physiological interpretation of cardiotocograph (CTG): Inter-observer and “Observer-AI” agreements in recognising types of fetal hypoxic stress
Main Article Content
Abstract
Introduction: Interobserver reliability in interpreting cardiotocographs (CTGs) using traditional categorization into "normal," "suspicious," and "pathological" is typically very low ranging from Kappa 0.3 to 0.6. Physiological CTG interpretation focuses on identifying specific features of different types of fetal hypoxic stress and a combination of features which are associated with adverse perinatal outcomes.
Objective: To evaluate the agreement among members of the Editorial Board (EBM) of the international expert consensus statement on physiological CTG interpretation, members of the international expert consensus panel (ICP), and the Tweris Mini App (TMA), which is an AI-based CTG interpretation tool developed based on international expert consensus statement.
Materials & Methods: Thirty 10–15-minute CTG trace segments, representing different types of fetal hypoxic stress (chronic, gradually evolving compensated, gradually evolving decompensated, subacute, and acute) and abnormal CTG patterns (atypical sinusoidal or the “Poole Shark Teeth”, typical sinusoidal and the ZigZag patterns), were independently reviewed by 3 editorial board members and 3 international expert consensus panel members. An orthopedic surgeon independently analyzed the same traces using the TMA. Fleiss' Kappa and Z-scores were used for statistical analysis.
Results: Inter-observer agreement was 0.8 (95% CI: 0.72-0.87, p < .001) among EBM and 0.68 (95% CI: 0.60-0.76, p < .001) among ICP, with a statistically significant difference between these groups (p < .05). Agreement between EBM and the Tweris Mini App was higher than between ICP and the Tweris Mini App (0.81 vs 0.73, p = .06).
Conclusion: The inter-observer agreement when using physiological CTG interpretation surpasses that of the inter-observer agreement reported with traditional systems of CTG classification, with higher interobserver agreement among editorial board members compared to international expert consensus panel members. There was a substantial agreement between editorial board members and the Tweris Mini app which was higher than between ICP and the Tweris Mini App. These findings highlight the potential of AI-assisted tools, such as the Tweris Mini App, based on physiological CTG interpretation, to provide expert-level diagnostic accuracy in clinical practice. The Tweris Mini App was found to be superior in consistently recognising rare fetal heart rate patterns.
Keywords:
cardiotocograph (CTG), physiological CTG, artificial intelligence (AI), hypoxia, false positive, Tweris Mini App (TMA)
Article Details
How to Cite
E, Chandraharan et al.
Physiological interpretation of cardiotocograph (CTG): Inter-observer and “Observer-AI” agreements in recognising types of fetal hypoxic stress.
Medical Research Archives, [S.l.], v. 12, n. 11, nov. 2024.
ISSN 2375-1924.
Available at: <https://esmed.org/MRA/mra/article/view/5980>. Date accessed: 12 dec. 2024.
doi: https://doi.org/10.18103/mra.v12i11.5980.
Section
Research Articles
The Medical Research Archives grants authors the right to publish and reproduce the unrevised contribution in whole or in part at any time and in any form for any scholarly non-commercial purpose with the condition that all publications of the contribution include a full citation to the journal as published by the Medical Research Archives.
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50. Chandraharan E. Fetal Electrocardiograph (ST-Analyser or STAN): Is it time for the Requiem?. J Clin Med Surgery. 2023; 3(2): 1111.
51. Brocklehurst P, Field D, Greene K, Juszczak E, Kenyon S, Linsell L, Mabey C, Newburn M, Plachcinski R, Quigley M, Steer P, Schroeder L, Rivero-Arias O. Computerised interpretation of the fetal heart rate during labour: a randomised controlled trial (INFANT). Health Technol Assess. 2018 Feb;22(9):1-186.
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55. Chandraharan E. Rational Approach to electronic fetal monitoring in all resource settings. SL J Obst & Gynaecol 2010; 32: 77-84
56. McDonnell S, Chandraharan E, The Pathophysiology of CTGs and Types of Intrapartum Hypoxia, Current Women`s Health Reviews 2013; 9(3).
57. Pinas A, Chandraharan E. Continuous cardiotocography during labour: analysis, classification and management. Best Pract Res Clin Obstet Gynaecol 2016;30:33–47.
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60. Pereira S, Chandraharan E. Recognition of chronic hypoxia and pre-existing foetal injury on the cardiotocograph (CTG): urgent need to think beyond the guidelines. Porto Biomed J 2017;2: 124–9.
61. Oikonomou M, Chandraharan E. Fetal heart rate monitoring in labor: from pattern recognition to fetal physiology. Minerva Obstet Gynecol 2021;73:19–33.
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63. Bolten M, Chandraharan E. The Significance of ‘Non-Significant’ Meconium Stained Amniotic Fluid (MSAF): Colour versus Contents. J Adv Med Med Res. 2019. doi:10.9734/jammr/2019/v30i530192
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66. Al Fahdi B & Chandraharan E. True vs Spurious Intrapartum Fetal Heart Rate Accelerations on the Cardiotocograph (CTG): An Urgent Need for Caution. Glob J Reprod Med. 2020; 7 (5): 5556722. DOI: 10.19080/GJORM.2019.07.555722.
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68. Saeed F, Abeysuriya S, Chandraharan E. Erroneous Recording of Maternal Heart Rate as Fetal Heart Rate During Second Stage of Labour: Isn’t it Time to Stop this? J Biomed Res Environ Sci. 2021 May 11; 2(5): 315-319. doi: 10.37871/jbres1233.
69. Nurani R, Chandraharan E, Lowe V, Ugwumadu A, Arulkumaran S. Misidentification of maternal heart rate as fetal on cardiotocography during the second stage of labor: the role of the fetal electrocardiograph. Acta Obstet Gynecol Scand. 2012 Dec;91(12):1428-32. doi: 10.1111/j.1600-0412.2012.01511.x. Epub 2012 Sep 18.
70. Ingram C, Gupta N, Mustafa S, Singh M, Chandraharan E. Impact of Physiological CTG Guidelines on Intrapartum Hypoxic injuries and brain cooling. World Congress of the Royal College of Obstetricians and Gynaecologists (RCOG) 2021.
71. Jia YJ, Ghi T, Pereira S, Gracia Perez-Bonfils A, Chandraharan E. Pathophysiological interpretation of fetal heart rate tracings in clinical practice. Am J Obstet Gynecol. 2023 Jun;228(6):622-644.
72. Reeves K, Scully R, Dutta A, Bullen-Bull R, Singh M, Chandraharan E. Training and support on Physiological CTG Interpretation: Does it reduce the hypoxic encephalopathy (HIE) rate? European Congress on Intrapartum Care. 2021.
73. Chandraharan E, Evans SA, Krueger D, Pereira S, Skivens S, et al. (2018) Physiological CTG interpretation. Intrapartum Fetal Monitoring Guideline. https://physiological-ctg.com/guideline.html.
74. Zamora Del Pozo C, Chóliz Ezquerro M, Mejía I, Díaz de Terán Martínez-Berganza E, Esteban LM, Rivero Alonso A, Castán Larraz B, Andeyro García M, Savirón Cornudella R. Diagnostic capacity and interobserver variability in FIGO, ACOG, NICE and Chandraharan cardiotocographic guidelines to predict neonatal acidemia. J Matern Fetal Neonatal Med. 2022 Dec;35(25):8498-8506.
75. Ghi T, Di Pasquo E, Dall’Asta A, et al. Intrapartum fetal heart rate between 150 and 160 bpm at or after 40 weeks and labor outcome. Acta Obstet Gynecol Scand 2021;100:548–54.
76. Preti M, Chandraharan E. Importance of fetal heart rate cycling during the interpretation of the cardiotocograph (CTG). Int J Gynecol Reprod Sci 2018;1:10–2.
77. Pereira S, Lau K, Modestini C, Wertheim D, Chandraharan E. Absence of fetal heart rate cycling on the intrapartum cardiotocograph (CTG) is associated with intrapartum pyrexia and lower Apgar scores. J Matern Fetal Neonatal Med. 2021 Jun 22:1-6.
78. Gracia-Perez-Bonfils A, Martinez-Perez O, Llurba E, Chandraharan E. Fetal heart rate changes on the cardiotocograph trace secondary to maternal COVID-19 infection. Eur J Obstet Gynecol Reprod Biol. 2020 Sep;252:286-293.
79. di Pasquo E, Commare A, Masturzo B, Paolucci S, Cromi A, Montersino B, Germano CM, Attini R, Perrone S, Pisani F, Dall'Asta A, Fieni S, Frusca T, Ghi T. Short-term morbidity and types of intrapartum hypoxia in the newborn with metabolic acidaemia: a retrospective cohort study. BJOG. 2022 Oct;129(11):1916-1925.
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81. Yatham SS, Whelehan V, Archer A, Chandraharan E. Types of intrapartum hypoxia on the cardiotocograph (CTG): do they have any relationship with the type of brain injury in the MRI scan in term babies? J Obstet Gynaecol. 2020 Jul;40(5):688-693.
82. Pereira S, Patel R, Zaima A, Tvarozkova K, Chisholm P, Kappelou O, Evanson J, Chandraharan E, Wertheim D, Shah DK. Physiological CTG categorization in types of hypoxia compared with MRI and neurodevelopmental outcome in infants with HIE. J Matern Fetal Neonatal Med. 2022 Dec;35(25):9675-9683.
83. Chandraharan E. Physiological Interpretation of Cardiotocograph: Does the Emerging Scientific Evidence Suggest a Reversal in the “Thunder and Lightning” Phenomenon?. J Clin Med Surgery. 2023; 3(1): 1098.
84. Jia YJ, Chen X, Cui HY, Whelehan V, Archer A, Chandraharan E. Physiological CTG interpretation: the significance of baseline fetal heart rate changes after the onset of decelerations and associated perinatal outcomes. J Matern Fetal Neonatal Med. 2021 Jul;34(14):2349-2354.
85. Gracia-Perez-Bonfils A, Vigneswaran K, Cuadras D, Chandraharan E. Does the saltatory pattern on cardiotocograph (CTG) trace really exist? The ZigZag pattern as an alternative definition and its correlation with perinatal outcomes. J Matern Fetal Neonatal Med. 2019 Nov 13:1-9.
86. Galli L, Dall'Asta A, Whelehan V, Archer A, Chandraharan E. Intrapartum cardiotocography patterns observed in suspected clinical and subclinical chorioamnionitis in term fetuses. J Obstet Gynaecol Res. 2019 Dec;45(12):2343-2350. doi: 10.1111/jog.14133. Epub 2019 Oct 16.
87. Sukumaran S, Pereira V, Mallur S, Chandraharan E. Cardiotocograph (CTG) changes and maternal and neonatal outcomes in chorioamnionitis and/or funisitis confirmed on histopathology. Eur J Obstet Gynecol Reprod Biol. 2021 May;260:183-188. doi: 10.1016/j.ejogrb.2021.03.029. Epub 2021 Mar 30.
88. di Pasquo E, Fieni S, Chandraharan E, Dall'Asta A, Morganelli G, Spinelli M, Bettinelli ML, Aloe R, Russo A, Galli L, Perrone S, Ghi T. Correlation between intrapartum CTG findings and interleukin-6 levels in the umbilical cord arterial blood: A prospective cohort study. Eur J Obstet Gynecol Reprod Biol. 2024 Mar;294:128-134.
89. Chandraharan E, Pereira S, Ghi T, Gracia Perez-Bonfils A, Fieni S, Jia YJ, Griffiths K, Sukumaran S, Ingram C, Reeves K, Bolten M, Loser K, Carreras E, Suy A, Garcia-Ruiz I, Galli L, Zaima A. International expert consensus statement on physiological interpretation of cardiotocograph (CTG): First revision (2024). Eur J Obstet Gynecol Reprod Biol. 2024 Oct 2;302:346-355. doi: 10.1016/j.ejogrb.2024.09.034. Epub ahead of print.
90. Kikuchi H, Noda S, Katsuragi S, Ikeda T, Horio H. Evaluation of 3-tier and 5-tier FHR pattern classifications using umbilical blood pH and base excess at delivery. PLoS One 2020;15:e0228630.
91. Cappe M, Deruelle P, Depret S, Houfflin-Debarge V, Ghesquière L, Garabedian C. Fetal heart rate classification in routine use: Do your prefer a 3-tier or a 5-tier classification? J Gynecol Obstet Hum Reprod. 2018 Nov;47(9):477-480.
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