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The changing landscape of cardiotocography (CTG) and the impact on midwifery expert witnesses
- Nov 6, 2024
- Latest Journal
by Gemma McIntyre - Somek & Associates
The monitoring of a baby using a cardiotocograph (or CTG as it is more commonly known) during the intrapartum period first became usual practice in the 1970’s (Gauge and Henerson, 2004) and has developed over time to become a tool, which is now commonplace on every labour ward. Student midwives are taught about CTG interpretation throughout their undergraduate degree programmes, midwives have a yearly update and most Trusts hold regular CTG teaching sessions, yet CTG interpretation and escalation continues to be one of the top themes in cases reported to NHS Resolution Early Notification Scheme (NHS Resolution, 2019), Royal College of Obstetricians and Gynaecologists (RCOG) Each Baby Counts Scheme (RCOG, 2020) and Maternity and Newborn Safety Investigations (MNSI) (Healthcare Safety Investigation Branch, 2023). In response to this there have been changes to national guidance, developments in education, three safety bundles which include fetal monitoring as an element and a focus on achieving these ambitions as part of the Maternity Incentive Scheme. This changing landscape must be considered by all midwifery expert witnesses when reviewing cases and providing expert witness reports and testimony, as to what was current practice for a reasonable and responsible midwife at the time of the incident. This article will explore some of the key changes.
Antenatal fetal monitoring and use of computerised CTGs.
When I first qualified in 2012 there was very limited guidance on how to interpret antenatal CTG traces. National Institute for Health and Clinical Excellence [NICE], (2007) guidance on intrapartum care and NICE (2008) guidance on antenatal care made no reference to interpretation of antenatal CTG traces and it was dependant on the Trust in which a midwife was working to produce local guidance. In the Trust where I first worked we were fortunate to have clear guidance for interpreting and categorising antenatal CTG traces as either normal or abnormal, but this was not always commonplace. One tool used to overcome this was the use of computerised CTG analysis, also known as Dawes Redman Criteria (DRC). This is a software tool which has a bank of over 100,000 CTG traces at various gestations and once some baseline data is entered it uses this to perform a numeric analysis and robust interpretation of the CTG trace.
In my experience, in the Trust where I worked, in 2012 the use of computerised CTG analysis was well embedded in the antenatal day assessment unit and would sometimes be used on the antenatal ward depending on how confident the midwife felt about using it. There was limited training and guidance on how to use it and I remember some midwives did not trust it and preferred their own interpretation.
By 2019 national guidance (NHS England, 2019) was recommending its usage to reduce the risk of human error when interpreting antenatal CTG traces. The use of computerised CTG analysis then became used regularly on the antenatal ward, particularly during induction of labour. The use of DRC is very specific in that it can only be used when there is no uterine activity. The tool is not designed to be used in labour; of course the difficulty comes in defining when labour begins. Many midwives interpreted this to mean when a woman was identified as being in established labour, with regular contractions and with her cervix being 4cm or more dilated.
MNSI reports began to highlight this to Trusts and in 2023 the Dawes Redman education site provided a statement on the use of computerised CTG analysis, which clearly set out that DRC can be used prior to the administration of the first vaginal prostaglandin in induction of labour, providing there is no uterine activity (Nuffield Department of Women's & Reproductive Health, 2023). It can also be used after a stretch and sweep and when a mechanical method to induce labour is used, again providing there is no uterine activity. NHS Resolution (2023) shared a case story based on a case when antenatal computerised CTG monitoring contributed to the outcome. The aim of this was to raise awareness of the dangers of using DRC when uterine contractions are present.
For the expert witness this means considering what the accepted practice was at the time of the incident when considering if performing or not performing DRC met the standard of the reasonable and responsible midwife.
When to perform a CTG?
Making the decision to commence continuous CTG monitoring in labour is often the role of the midwife. In order to determine which women are suitable for intermittent auscultation and which require continuous monitoring is based on a thorough and continuous risk assessment. The risk assessment for labour includes a consideration of any risk factors during pregnancy and the current presentation of the woman. Midwives who qualified before me may remember how an admission CTG would be performed on every woman attending in labour; NICE (2007) discouraged the use of this and today it would be very unusual to see this practice.
NICE (2022) currently provides a list of antenatal maternal and fetal risk factors as a guide to determine which clinical situations indicate continuous CTG monitoring in labour should be offered. This also includes a caveat that if other concerns not listed are present then, following a multi-disciplinary review, the offer of continuous CTG monitoring can be considered.
As labour progresses the role of the midwife is to continue reviewing the risk assessment and consider any risk factors which have developed in the intrapartum period. NICE Intrapartum care guidance in 2014 and 2017 both recommended a documented systematic assessment of the mother and baby at a minimum of hourly and more frequently if there are concerns (NICE, 2014, 2017). In 2022 NICE published ‘Fetal Monitoring in Labour’ guideline, which is a stand-alone guideline separate from intrapartum care guideline (NICE, 2022). This also includes recommendation of an hourly assessment of the mother and baby during labour and specifies what should be taken into account as part of the assessment and which conditions indicate a move to continuous CTG monitoring.
In my experience, although the latest guidance may provide written direction on what to cover, the ordinary midwife would have been expected to perform a comprehensive risk assessment encompassing all of the elements listed prior to publication of this guideline. The midwifery expert witness must therefore consider what the actions would have been for the reasonable and responsible midwife when considering cases prior to 2022.
There are some exceptions to this rule and one which I have observed in several cases is the assessment of blood stained liquor. NICE (2007, 2014, 2014, 2022) all indicate that fresh bleeding in labour or any vaginal blood loss other than a show is considered an intrapartum risk factor and continuous CTG monitoring would be required. In my experience midwives often have the tendency to describe ‘pinky liquor’ or to document ‘show evident’ on multiple occasions. In this way the language used has normalised a risk factor and does not always allow for consideration of the significance of multiple small amounts of blood loss. Healthcare Safety Investigations Branch (2023) highlights this as a theme in risk assessment in the intrapartum period of care. This needs careful consideration as an expert witness and the question I ask of myself is ‘when did I alter my practice to reflect this?’ It can be difficult to determine how effectively engrained ways of working such as this are challenged and new learning disseminated to embed new practice. As an expert I think back to a situation where I experienced this and consider my actions. I then use this to determine what was current expected practice at that time.
Continuous means continuous
As a clinical midwife caring for a woman having continuous CTG monitoring, usually using a wired machine and encouraging fluids, the same issue would occur time and again. How could I support women to use the toilet and so promote independence, mobilisation and preservation of dignity, not to mention reduce the risk of bladder damage, when I needed to continuously monitor their baby?
As a student midwife I was shown how to unplug the transducers, wrap them up and hand them to the woman and leave the CTG running whilst I assisted her to the toilet. Once she returned to the bed (freshly made with a clean inco sheet and a fluffed up pillow, of course) I would dutifully plug the transducers back into the machine and write in the gap on the CTG paper ‘up to toilet’. I would think nothing of this and, along with my colleagues, continued this practice with no real concerns about what could be happening to the fetal heart rate whilst there was no monitoring on. There were always situations where I would consider that the risk of disconnecting the CTG for a toilet break were too great, this would usually be when there were concerns about the CTG trace or when the woman had epidural anaesthesia in place. In this instance I would offer intermittent catheterisation and on the whole women accepted this. It was very unusual to offer a bedpan and there was no commode on the unit. As telemetry became more available this could be used, however there was initially only 1 machine on the unit which was big and heavy and didn’t always work very well, so myself and most colleagues tended to use this only when necessary.
In 2019 I became aware of a case where a midwife had done exactly as I did and disconnected the CTG whilst a woman she was providing care for used the toilet. On her return she plugged back in the CTG and the fetal heart rate was no longer recording. Initially this did not cause concern as the transducer does sometimes need to be moved to accurately record the heart rate, especially following reposition of the woman. When the fetal heart rate was located there was an ongoing fetal bradycardia. The emergency bell was pulled and the baby’s birth was expediated. When reviewing the case it became apparent that no one could determine how long the fetal bradycardia had been ongoing and this impacted on the decision making of the obstetric team. This changed my practice and for me now ‘continuous means continuous’, after all if a woman is being monitored using a continuous CTG this is because increased risk factors are present.
The changes in interpretation and importance of categorisation
Further challenges in CTG landscape include the various changes made to how CTG traces are assessed, interpreted, categorised and what, if any, escalation is required. Although there have been other methods used for CTG interpretation the majority of my experience is in using the NICE guidelines and I will focus on some of the key changes within this.
As a midwife, CTG assessment is a continuous process throughout caring for a woman in labour. A formal assessment may be documented at least hourly in the records but in reality the midwife is continually observing the CTG and making notes, adjustments or acting if there are concerns. Until the updated NICE guidance in 2022, assessment was of four key features; baseline rate, variability, accelerations and decelerations. Each feature was considered individually, assessed and scored as either reassuring, non-reassuring or abnormal with the scores added up to determine what the overall categorisation was. The three overall categorisations have not altered since the 2007 guidance (NICE, 2007), and are ‘Normal, Suspicious or Pathological’. Changes between the guidance in 2007, 2014 and 2017 included the acceptance of a baseline heart rate of between 100-160bpm as a reassuring feature rather than non-reassuring, and then back to 110-160bpm in 2017 (NICE, 2007, 2014, 2017). There were also changes to the assessment of decelerations with more detail given and some of the language used changing. There was more detailed guidance about what actions to take with each categorisation, including who to escalate to and actions for other clinicians following this such as fetal blood sampling, conservative measures or expediting the birth of the baby (NICE, 2017).
The standalone intrapartum fetal monitoring guidance introduced in 2022 (NICE, 2022) made several changes to both language and parameters for each feature and overall categorisation. The assessment of the features became colour coded as white, amber or red, rather than reassuring, non-reassuring or abnormal. The overall categorisations of normal, suspicious and pathological have remained the same.
A significant change was that assessment of the rate of contractions was included in the systematic assessment as a feature, which had not previously been the case. The parameters included the presence of 5 or more contractions in a ten minute period an amber feature (NICE, 2022) whereas this had previously been considered the aim when using oxytocin to stimulate contractions (NICE, 2007, 2014, 2017).
A further change to the parameters was a change to what constitutes a normal baseline. Previously a baseline of 110-160pm was considered reassuring, with 160-180bpm non-reassuring and above 180bpm abnormal (NICE, 2017). In the 2022 guidance a baseline rate above 160bpm is considered a red feature and makes the overall categorisation of the CTG pathological (NICE, 2022).
In clinical practice, in the Trust where I work, these changes, along with others from the updated guidance, have now been incorporated into the electronic records system, which has allowed me and my colleagues to embed them into practice easily. When reviewing cases I take into account what the guideline was at the time, my understanding of it and when my practice altered. My Trust’s electronic system was not updated until May 2023, however this change was disseminated during clinical shifts, newsletter and on training days, not to mention that a midwife has a responsibility to remain up to date on changes to local and national guidance, so I consider that a reasonable and responsible midwife should have embedded this into their clinical practice by mid-2023, as I did.
Whilst the knowledge and understanding of CTG traces is growing there will be continued changes to guidelines. There are now an increased amount of things for midwives to consider when caring for a woman on continuous CTG monitoring. Overall, I find the emphasis the new guidance places on the CTG as a tool to be used in conjunction with a holistic assessment of the woman, including involving the woman in the process and allowing for concerns not mentioned in the guideline to be taken into consideration, very much needed. Almost every midwife can recount a time when they have been in the room and something just doesn’t feel quite right but the CTG doesn’t quite meet the criteria for escalation. This updated guideline provides some first steps in supporting midwives to escalate these concerns.
What does this mean for the midwifery expert witness?
When thinking about what the key takeaways are for the expert witness, it’s helpful to remember that CTG interpretation is not an exact science; very pathological CTG traces are generally easy to spot but it’s the ones that could be interpreted either way that cause more differences in opinion between clinicians.
My five top tips are;
• Look at the CTG and consider it based on the national guidance that was current at the time. I now find it more difficult to remember the parameters for the difference features for a case in 2013 than I do for a case in 2021 or 2023. To assist with this I created a quick glance guide with the different parameters for each feature so I can assess the trace based on what I knew at that time. This has proved invaluable.
• Consider not just local guidance but also what was usual practice at that time - for an example, my above point about use of the toilet when performing continuous CTG monitoring. Local guidance can sometimes be very helpful here, like in the case of use of Dawes Redman criteria during induction of labour.
• Remember what the role of the midwife is. It’s easy to look at a CTG and think “we would have had that baby delivered in my workplace.” The role of the midwife is to perform an initial risk assessment, commence CTG monitoring effectively, perform an ongoing holistic risk assessment, ensure fresh eyes occurs hourly, categorise the CTG trace and escalate concerns to a senior midwife and/or the obstetric team. It isn’t to determine if the decision for a caesarean birth or an assisted vaginal birth should have been performed - that is outside of the scope of practice for a standard midwife and you will need to defer to an expert obstetrician.
• Look at when you think escalation should have occurred when looking at timings. Use the actual timings to assist with working backwards from when the baby was born. For example, if the baby was born at 03:30 and the obstetric team made the decision at 03:20 after it was escalated to them at 03:15 but you consider no reasonable and responsible midwife would have failed to have escalated at 02:45 (30 minutes earlier), then in conclusion the time of birth, in your opinion, would have been by 03:00 (30 minutes earlier).
• Don’t be afraid to disagree with other experts but don’t expect them to always agree with you! CTG interpretation is complex and there are often no right answers. This may be very important when attending Early Notification Scheme summits or joint expert meetings.
References:
Gauge, S., Henderson, C. (2004) CTG Made Easy. 2nd Edition. Churchill Livingstone. China.
Healthcare Safety Investigation Branch, (HSIB) (2023) Maternity Investigation Programme Year in Review 2022/23. [Online] Available at Maternity Investigation Programme Year in Review 2022/23 (mnsi.org.uk) (Accessed 10th September 2024)
Healthcare Safety Investigation Branch, (HSIB) (2023) Assessment of risk during the maternity pathway. [Online] Available at Assessment of risk during the maternity pathway (mnsi.org.uk) (Accessed 10th September 2024)
National Institute of Health and Care Excellence (NICE) (2007) Intrapartum care. Clinical Guideline [CG55] [Archived] [Online] Available at [ARCHIVED CONTENT] CG55 Intrapartum care: NICE guideline (nationalarchives.gov.uk) (Accessed 10th September 2024)
National Institute of Health and Care Excellence (NICE) (2008) Antenatal Care for Uncomplicated Pregnancies– Clinical Guideline [CG62] [Archived] [Online] Available at [ARCHIVED CONTENT] (nationalarchives.gov.uk) (Accessed 10th September 2024)
National Institute of Health and Care Excellence (NICE) (2014) Intrapartum care: care of healthy women and their babies during childbirth- Clinical Guideline [CG190] [Archived] [Online] Available at [ARCHIVED CONTENT] Intrapartum care: care of healthy women and their babies during childbirth | 1-recommendations | Guidance and guidelines | NICE (nationalarchives.gov.uk) (Accessed 10th September 2024)
National Institute of Health and Care Excellence (NICE) (2017) Intrapartum care: care of healthy women and their babies during childbirth- Clinical Guideline [CG190] [Archived] [Online] Available at [ARCHIVED CONTENT] (nationalarchives.gov.uk) (Accessed 10th September 2024)
National Institute of Health and Care Excellence (NICE) (2022) Fetal monitoring in labour- NICE guideline [NG229] [Online] Available at Fetal monitoring in labour (nice.org.uk) (Accessed 10th September 2024)
NHS England (2019) Saving Babies Lives: care bundle version two. [Online] Available at Saving-Babies-Lives-Care-Bundle-Version-Two-Updated-Final-Version.pdf (england.nhs.uk) (Accessed 10th September 2024)
NHS Resolution (2019) The Early Notification Scheme Progress Report: Collaboration and Improved Experience for Families. [Online] Available at The Early Notification scheme progress report: collaboration and improved experience for families (resolution.nhs.uk) (Accessed 10th September 2024)
NHS Resolution (2023) Case story: Antenatal computerised CTG monitoring. [Online] Available at Case story Antenatal computerised CTG monitoring (resolution.nhs.uk) (Accessed 10th September 2024)
Nuffield Department of Women's & Reproductive Health (2023) Use of the Oxford Dawes-Redman computerised CTG analysis system around labour. [Online] Available at Dawes-Redman+and++Uterine+Activity.pdf (squarespace.com) (Accessed 10th September 2024)
Royal College of Obstetricians and Gynaecologists (2020) Each Baby Counts: 2020 Final Progress Report. [Online] Available at ebc-2020-final-progress-report.pdf (rcog.org.uk) (Accessed 10th September 2024)
Author
Gemma McIntyre
Registered Midwife, Professional Midwifery Advocate
BSc (Hons) Midwifery, MSc Health Studies
Gemma qualified as a registered midwife in 2012 and enjoyed spending time rotating through the antenatal and postnatal wards, community midwifery, antenatal day assessment unit and clinic before settling in her favourite place on labour ward. During her time working clinically, Gemma enjoyed gaining additional skills in mentorship, examination of the newborn, advanced clinical practice and newborn life support alongside the more recognised skills such as suturing, CTG interpretation, caring for bereaved families and managing emergency situations. In 2016 Gemma became involved in some additional governance and audit tasks, which led to her successful appointment as a specialist midwife in clinical skills and patient safety in 2017. After 2 years in this role Gemma decided to take a leap and began working as a maternity investigator for what was previously known as the Healthcare Safety Investigation Branch (HSIB), before it gained its new name of Maternity and Newborn Safety Investigations (MNSI) in October 2023. Gemma has very much enjoyed this role and the involvement she has with families and clinicians. To maintain her clinical practice she has regularly worked as a bank midwife at her local trust, usually on labour ward but occasionally she can be found on the antenatal or postnatal ward and even pregnancy assessment. Gemma joined Somek and Associates in August 2023 and has thoroughly enjoyed her new role. She is now feeling more confident in her report writing and this has been reflected by the positive feedback she has received from both her associate trainer and from clients.
