Physiological Interpretation of Cardiotocograph (CTG): The role of the intrapartum “FIT- CAT”
Main Article Content
Abstract
Physiological interpretation of cardiotocograph (CTG) involves determining the combination or sequence of features of the fetal heart rate to recognise different types of fetal hypoxic or non-hypoxic (e.g., chorioamnionitis) stresses, as well as scrutinising the CTG trace to differentiate features suggestive of fetal compensatory responses from decompensation. The Fetal Monitoring Checklist was recommended in 2017, and this has been recently endorsed by the International Expert Consensus Statement on Physiological Interpretation of CTG produced by more than 50 CTG experts from over 20 countries. The aim of the Fetal Monitoring Checklist is to exclude or to identify features suggestive of pre-existing fetal compromise by assessing the oxygenation of fetal central organs, placental function and the wider clinical context. This enables the frontline clinicians to ask the question “Is THIS fetus FIT to undertake the progressively hypoxic journey of human labour?” However, some pre-existing risk factors may manifest after the onset of established labour due to the super-imposed hypoxic stress. Similarly, intra-amniotic infection following a recent spontaneous prelabour rupture of membranes may be silent during the incubation period, but it may manifest during labour. In such cases, the use of the Fetal Monitoring Checklist may lead to the clinicians concluding that the “Fetus is FIT for Labour”, although, there is increased risk of fetal compromise with the passage of time and intrapartum super-imposed hypoxic stress. The intrapartum “FIT-CAT” (FIT for labour -Clinical Anticipation Tool) is designed to aid frontline clinicians to anticipate the changes on the CTG which are likely to occur during labour, based on the identified antenatal or intrapartum risk factors. This intrapartum anticipation tool may enable the timely recognition of features on the CTG which heralds the onset of fetal decompensation in fetuses who are deemed “FIT” to commence labour with pre-existing risk factors and/or develop intrapartum risk factors. Prompt recognition and appropriate management based on individualisation of care and the understanding of the impact of clinical context on the CTG trace may help improve perinatal outcomes.
Article Details
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.
References
2. Chandraharan E (2019) Intrapartum care: An urgent need to question historical practices and ‘non-evidence’-based, illogical foetal monitoring guidelines to avoid patient harm. Journal of Patient Safety and Risk Management 24(5): 210-217.
3. 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 Jul-Aug;2(4):124-129.
4. Chandraharan E. Physiological interpretation of CTG: From Knowledge to Practice. Volumes 1-3. Glob Acad Med Edu Train, London, KDP. 2022 (https://www.amazon.co.uk/s?k=chandraharan&crid=1VKO4VCPZJ5IV&sprefix=chandraharan%2Caps%2C310&ref=nb_sb_noss_1)
5. 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 Nov;302:346-355.
6. Chandraharan E. Updated NICE Cardiotocograph (CTG) guideline: Is it suspicious or pathological? J Clin MedSurgery. 2023; 3(2): 1129
7. 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 Jan 13;294:128-134.
8. Ghi T, Fieni S, Ramirez Zegarra R, Pereira S, Dall'Asta A, Chandraharan E. Relative uteroplacental insufficiency of labor. Acta Obstet Gynecol Scand. 2024 Oct;103(10):1910-1918. doi: 10.1111/aogs.14937.
9. Eidelman AI, Nevet A, Rudensky B, Rabinowitz R, Hammerman C, Raveh D, Schimmel MS. The effect of meconium staining of amniotic fluid on the growth of Escherichia coli and group B streptococcus. J Perinatol. 2002;22(6):467- 71.
10. 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
11. Pinas A, Chandraharan E. Continuous cardiotocography during labour: Analysis, classification and management. Best Pract Res Clin Obstet Gynaecol. 2016 Jan;30:33-47.
12. Chandraharan E, Arulkumaran S. Prevention of birth asphyxia: responding appropriately to cardiotocograph (CTG) traces. Best Pract Res Clin Obstet Gynaecol. 2007 Aug;21(4):609-24.
13. Chandraharan E. Handbook of CTG interpretation: From patterns to Physiology. First Edition, Cambridge, Cambridge University Press, 2017.
14. Griffiths K, Gupta N, Chandraharan E. Intrapartum fetal surveillance: a physiological approach, Obstetrics, Gynaecology & Reproductive Medicine, Volume 32, Issue 8, 2022,Pages 179-187,
15. 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.
16. Tarvonen M, Hovi P, Sainio S, Vuorela P, Andersson S, Teramo K. Factors associated with intrapartum ZigZag pattern of fetal heart rate: A retrospective one-year cohort study of 5150 singleton childbirths. Eur J Obstet Gynecol Reprod Biol. 2021 Mar;258:118-125.
17. Chandraharan E. Physiological CTG Masterclass Course Manual. Glob Acad Med Edu Train, London, KDP. 2023. https://www.amazon.co.uk/Physiological-CTG-Masterclasses-Course-Manual/dp/B0C9S99Q3D/ref=sr_1_5?dib=eyJ2IjoiMSJ9.QhJ78JEiv-NVrMd2RUsft6y7dLxSG66qtjE4ZiMw1uhh5iEX7GEsB-a7lDiPAmhL6Zed_7W2FbluQumq2ciYh1zFbk2OQdAb0Kz1DfQDcfI.it1-z6e-mBiAOhDYjgUdOlBltBtCvD3ZkFWCUKzZEkU&dib_tag=se&keywords=chandraharan&qid=1705689835&sr=8-5
18. Royal College of Obstetricians and Gynaecologists. Each Baby Counts: 2020 Final Progress Report. London: RCOG; 2021.( https://www.rcog.org.uk/globalassets/documents/guidelines/research--audit/each-baby-counts/ebc-2020-final-progress-report.pdf)
19. Chandraharan E. Updated NICE Cardiotocograph (CTG) guideline: Is it suspicious or pathological?. J Clin MedSurgery. 2023; 3(2): 112.
20. Evidence-based Clinical Guideline No. 8 The use and interpretation of CTG in intrapartum fetal surveillance (2001). RCOG Press, 2001.
21. National Institute of Clinical Excellence. Intrapartum care: care of healthy women and their babies during labour. NICE Clinical Guideline, December 2014. https://www.nice.org.uk/guidance/cg190/resources/intrapartum-care-for-healthy-women-and-babies-pdf-35109866447557
22. Physiological interpretation of CTG: From Knowledge to Practice. Volumes 3: Avoiding medicolegal pitfalls. Glob Acad Med Edu Train, London, KDP. 2022 (https://www.amazon.co.uk/s?k=chandraharan&crid=1VKO4VCPZJ5IV&sprefix=chandraharan%2Caps%2C310&ref=nb_sb_noss_1)
23. Intrapartum-related Deaths: 500 Missed Opportunities. Chapter In: 2006 Annual Report of the Chief Medical Officer. On the State of Public Health. Department of Health; 2007. (https://webarchive.nationalarchives.gov.uk/ukgwa/20130105021748/http:/www.dh.gov.uk/en/Publicationsandstatistics/Publications/AnnualReports/DH_076817)
24. Study of Stillbirth Claims by NHSLA (2009). https://silo.tips/download/study-of-stillbirth-claims-published-by-nhs-litigation-authority
25. Royal College of Obstetricians and Gynaecologists. Each Baby Counts: 2018 Progress Report. London: RCOG; 2018. (https://www.rcog.org.uk/media/dswjqyin/each-baby-counts-report-2018-11-12.pdf) .
26. Royal College of Obstetricians and Gynaecologists. Each Baby Counts: 2019 Progress Report. London: RCOG; 2020. (https://www.rcog.org.uk/media/qhzlelnc/each-baby-counts-2019-progress-report.pdf) .
27. Royal College of Obstetricians and Gynaecologists. Each Baby Counts: 2020 Final Progress Report. London: RCOG; 2021 (https://www.rcog.org.uk/media/a4eg2xnm/ebc-2020-final-progress-report.pdf).
28. Study of Stillbirth Claims by NHSLA (2009). https://silo.tips/download/study-of-stillbirth-claims-published-by-nhs-litigation-authority
29. NHSLA. Ten years of maternity claims: An analysis of NHS litigation authority data .2012. www.nhsla.com/safety/Documents/Ten%20Years%20of%20Maternity%20Claims%20%20An%20Analysis%20 of%20the%20NHS%20LA%20Data%20-%20October%202012.pdf .
30. NHS Resolution, The Early Notification scheme progress report: collaboration and improved experience for families, September 2019. https://resolution.nhs.uk/wp-content/uploads/2019/09/NHS-Resolution-Early-Notification-report.pdf
31. NHS Resolution. Annual Report & Accounts 2023/24. Published on 23 July 2024. https://resolution.nhs.uk/wp-content/uploads/2024/07/NHS-Resolution-Annual-report-and-accounts_23-24_Access.pdf
32. 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
33. Mitchell S, Chandraharan E, Meconium-stained amniotic fluid, Obstetrics, Gynaecology & Reproductive Medicine, Volume 28, Issue 4, 2018, Pages 120-124, ISSN 1751-7214.
34. Jonsson M, Nordén SL, Hanson U. Analysis of malpractice claims with a focus on oxytocin use in labour. Acta Obstet Gynecol Scand. 2007;86(3):315-9.
35. Sukumaran S, Jia YJ, Chandraharan E. Uterine Tachysystole, Hypertonus and Hyperstimulation: An urgent need to get the definitions right to avoid Intrapartum Hypoxic-Ischaemic Brain Injury. Glob J Reprod Med. 2021; 8(2): 5556735. DOI: 10.19080 /GJORM.2021.08.555735.
36. Badawi N, Kurinczuk JJ, Keogh JM, Alessandri LM, O’Sullivan F, Burton PR, et al. Intrapartum risk factors for newborn encephalopathy: the Western Australian case-control study. BMJ. 1998 Dec 5;317(7172):1554–8.
37. 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.202 1.03.029. Epub 2021 Mar 30.
38. Wu YW, EscobarGJ, Grether JK, Croen LA, Greene JD, Newman TB. Chorioamnionitis and cerebral palsy in term and near-term infants. JAMA. 2003;290:2677–84.
39. Wu YW, Colford JM Jr. Chorioamnionitis as a risk factor for cerebral palsy: a meta-analysis. JAMA. 2000;284:1417–24.
40. Mallard C, Hagberg H. Inflammation-induced preconditioning in the immature brain. Semin Fetal Neonatal Med. 2007 Aug;12(4):280–6.
41. Hagberg H, Peebles D, Mallard C. Models of white matter injury: comparison of infectious, hypoxic-ischemic, and excitotoxic insults. Ment Retard Dev Disabil Res Rev. 2002;8(1):30–8.
42. 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.
43. 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.20 21.03.029. Epub 2021 Mar 30.
44. 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.
45. Eklind S,Mallard C, LeverinAL, Gilland E, Blomgren K,Mattsby-Baltzer I, et al. Bacterial endotoxin sensitizes the immature brain to hypoxic–ischaemic injury. Eur J Neurosci. 2001 Mar;13(6) :1101–6.
46. Eklind S,Mallard C, Arvidsson P,Hagberg H. Lipopolysaccharide induces both a primary and a secondary phase of sensitization in the developing rat brain. Pediatr Res. 2005 Jul;58(1):112–6.
47. Yang L, Sameshima H, Ikeda T, Ikenoue T. Lipopolysaccharide administration enhances hypoxic-ischemic brain damage in newborn rats. J Obstet Gynaecol Res. 2004;30(2):142–7.
48. Yang L, Sameshima H, Ikeda T, Ikenoue T. Lipopolysaccharide administration enhances hypoxic-ischemic brain damage in newborn rats. J Obstet Gynaecol Res. 2004;30(2):142–7.
49. Coumans AB, Middelanis JS, Garnier Y, Vaihinger HM, Leib SL, Von Duering MU, et al. Intracisternal application of endotoxin enhances the susceptibility to subsequent hypoxic-ischemic brain damage in neonatal rats. Pediatr Res. 2003 May;53(5):770–5
50. Grether JK, Nelson KB. Maternal infection and cerebral palsy in infants of normal birth weight. JAMA. 1997 Jul;16(278):207–11.
51. Chandraharan E. Fetal scalp blood sampling during labour: is it a useful diagnostic test or a historical test that no longer has a place in modern clinical obstetrics? BJOG 2014;121:1056–60, discussion 1060–2.
52. Chandraharan E, Wiberg N. Fetal scalp blood sampling during labor: an appraisal of the physiological basis and scientific evidence. Acta Obstet Gynecol Scand 2014;93:544–7.
53. Chandraharan E. Should national guidelines continue to recommend fetal scalp blood sampling during labor?. J Matern Fetal Neonatal Med. 2016; 29(22):3682-3685. doi:10.3109/14767058.2016.1140740.
54. 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 Jan 13;294:128-134.
55. Chandraharan, E., & Bolten, M. (2024). Recognition of Chorioamnionitis on the Cardiotocograph (CTG): The role of the “Chorio Duck Score”. European Journal of Medical and Health Sciences, 6(1), 1–9.
56. Fetal Monitoring in Labor. NG224. National Institute of Health and Care Excellence (NICE). December 2022. https://www.nice.org.uk/guidance/ng229/resources/fetal-monitoring-in-labour-pdf-66143844065221.
57. Society for Maternal-Fetal Medicine (SMFM). Electronic address: [email protected]; Silver R, Craigo S, Porter F, Osmundson SS, Kuller JA, Norton ME. Society for Maternal-Fetal Medicine Consult Series #64: Systemic lupus erythematosus in pregnancy. Am J Obstet Gynecol. 2023 Mar ;228(3):B41-B60.
58. Giorgio E, De Oronzo MA, Iozza I, Di Natale A, Cianci S, Garofalo G, Giacobbe AM, Politi S. Parvovirus B19 during pregnancy: a review. J Prenat Med. 2010 Oct;4(4):63-6.
59. Kielaite D, Paliulyte V. Parvovirus (B19) Infection during Pregnancy: Possible Effect on the Course of Pregnancy and Rare Fetal Outcomes. A Case Report and Literature Review. Medicina (Kaunas). 2022 May 15;58(5):664.
60. Preti M, Chandraharan E. Importance of fetal heart rate cycling during the interpretation of the cardiotocograph (CTG). Int J Gynecol Reprod Sci. 2018;1(1):10–12.
61. 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. doi: 10.1080/14767058.2021.1940130.
62. Chandraharan E. Fetal scalp blood sampling should be abandoned: FOR: FBS does not fulfil the principle of first do no harm. BJOG. 2016 Oct;123(11):1770.
63. O'Heney J, McAllister S, Maresh M, Blott M. Fetal monitoring in labour: summary and update of NICE guidance. BMJ. 2022 Dec 16;379:o2854.
64. Alfirevic Z, Devane D and Gyte G. Continuous cardio- tocography (CTG) as a form of electronic fetal monitor- ing (EFM) for fetal assessment during labour. Cochrane Database Syst Rev 2013; 5: CD006066.
65. Holzmann M, Wretler S, Cnattingius S, Nordström L. Neonatal outcome and delivery mode in labors with repetitive fetal scalp blood sampling. Eur J Obstet Gynecol Reprod Biol. 2015 Jan;184:97-102.
66. Stål I, Wennerholm UB, Nordstrom L, Ladfors L, Wiberg-Itzel E. Fetal scalp blood sampling during second stage of labor - analyzing lactate or pH? A secondary analysis of a randomized controlled trial. J Matern Fetal Neonatal Med. 2022 Mar;35(6):1100-1107.
67. Al Wattar BH, Lakhiani A, Sacco A, et al; AB-FAB Study Group. Evaluating the value of intrapartum fetal scalp blood sampling to predict adverse neonatal out- comes: a UK multicentre observational study. Eur J Obstet Gynecol Reprod Biol 2019; 240: 62–67.
68. Chandraharan E. Physiological interpretation of CTG: From Knowledge to Practice. Volume 3: Avoiding Medico-legal Pitfalls. Glob Acad Med Edu Train, London, KDP. 2022 (https://www.amazon.co.uk/s?k=chandraharan&crid=1VKO4VCPZJ5IV&sprefix=chandraharan%2Caps%2C310&ref=nb_sb_noss_1)