Exploring the Evidence for Cardiotocography Monitoring
Published: 29 January 2020
Published: 29 January 2020
‘It’s amazing to note how much intervention and interference in pregnancy and birth is introduced without much evidence to support it. And yet it takes a phenomenal amount of research to even begin to dismantle and discontinue practices that aren’t helpful and may be harmful.
It’s long been assumed that routine cardiotocography (CTG) monitoring of all women in labour helps reduce neonatal morbidity (Mullins, Lees and Brocklehurst 2017).
Yet, evidence is growing that monitoring itself may be a potential source of harm, due to its association with high rates of unnecessary caesarean section.
Performing baseline monitoring, typically with about 20 minutes of continuous CTG is standard practice in many units and clearly has value in helping to identify babies who may benefit from an early delivery (Alfirevic et al. 2017).
It’s a long-established practice used to determine the most appropriate method of monitoring fetal wellbeing for the remainder of labour.
Questions are now being raised about the use of continuous monitoring in labour. For example, in seeking an answer to the question ‘Does electronic fetal heart rate, or CTG monitoring reduce perinatal mortality?’ Wickham (2019) reflects on three important points:
Devane et al. (2017) agree, suggesting that although many hospitals carry out CTG’s on admission, not only is there no evidence that this benefits women with low‐risk pregnancies, it may even increase the numbers of women having a caesarean section by about 20%.
They conclude that, contrary to current guidelines, the admission CTG should not be used for women who are assessed to be low risk on admission in labour.
For women with high-risk pregnancies however, continuous monitoring in labour can add valuable information to help keep mother and baby safe. The main indications for continuous CTG monitoring can helpfully be broken down as follows:
But as Alfirevic et al. (2017) suggest, beyond the initial assessment of fetal well-being, continuous CTG monitoring, without adequate clinical indication can potentially do more harm than good and is associated with a worrying rise in the rate of caesarean sections and instrumental births, both of which carry risks for mothers.
Continuous CTG also makes moving and changing positions difficult in labour and women are unable to use a birthing pool.
This can impact on women’s coping strategies, which in turn can raise stress levels and impact both fetal and maternal wellbeing.
Wickham (2019) also conducted a study looking at nine randomised controlled trials and 26 non-experimental studies and discovered that CTG monitoring during preterm labour was associated with a higher incidence of cerebral palsy.
Somewhat controversially they concluded that ‘research evidence failed to demonstrate perinatal benefits from intrapartum CTG monitoring for women at risk for poor perinatal outcome.’
That said, they also acknowledged that no one knows why CTG monitoring in preterm labour is associated with a higher incidence of cerebral palsy.
They also make the point that further research is urgently needed, suggesting that ‘until more people greet findings like these with openness and curiosity rather than defensiveness, we won’t find out’ (Wickham 2019).
The Royal College of Obstetricians & Gynaecologists (RCOG 2015) offer the following helpful evidence summary to guide practitioners.
Interestingly, the Royal College of Obstetricians & Gynaecologists (2015) conclude that performing a CTG as part of a standard admission process is not required as it increases the risk of caesarean section, and there is not enough evidence to determine if this affects outcomes for babies.
They conclude, therefore, that there is no current justification for offering an admission CTG for women receiving midwifery led care.
In the light of this they suggest that there is some evidence to recommend:
Even though the research seems to point clearly to the use of intermittent auscultation for fetal heart monitoring in low-risk women, the use of CTG monitoring continues to dominate in many maternity units.
Change often happens slowly in healthcare and whilst the weight of evidence still isn’t enough to move completely away from continuous monitoring, new initiatives are emerging. For example, Intelligent Structured Intermittent Auscultation (ISIA) offers midwives an informed decision-making framework to implement evidence-based fetal heart monitoring for low-risk women (Maude, Skinner and Foureur 2014).
As Wickham (2019) reflects:
‘It’s amazing to note how much intervention and interference in pregnancy and birth is introduced without much evidence to support it. And yet it takes a phenomenal amount of research to even begin to dismantle and discontinue practices that aren’t helpful and may be harmful. And we’re nowhere near there yet with electronic fetal monitoring.’
Anne is a freelance lecturer and medical writer at Mind Body Ink. She is a former midwife and nurse teacher with over 25 years’ experience working in the fields of healthcare, stress management and medical hypnosis. Her background includes working as a hospital midwife, Critical Care nurse, lecturer in Neonatal Intensive Care, and as a Clinical Nurse Specialist for a company making life support equipment. Anne has also studied many forms of complementary medicine and has extensive experience in the field of clinical hypnosis. She has a special interest in integrating complementary medicine into conventional healthcare settings and is currently an Associate Tutor, lecturing in Health Coaching and Medical Hypnosis at Exeter University in the UK. As a former Midwife, Anne has a natural passion for writing about fertility, pregnancy, birthing and baby care. Her recent publications include The Health Factor, Coach Yourself To Better Health and Positive Thinking For Kids. You can read more about her work at www.MindBodyInk.com. See Educator Profile