I’ve been asked questions similar to this many many times in conversations I have had with people about fetal monitoring. It seems to beg a yes / no answer, but the answer is far more complicated.
For starters, this question often feels to me as though the person asking it intends it as a trap. If I say no, you would think I was a bit hypocritical given the evidence I present. If I were to answer yes, it would be easy to portray me as a spiteful person with no concern for the wellbeing of babies. My interest in fetal monitoring stems from my experiences of seeing babies die or be damaged despite CTG use – so I’m not going to let people draw a chalk outline on the ground for me and take up a position they define.
This question is more complex than is seems as there are so many large gaps in our evidence base that it is difficult to make evidence-informed recommendations regarding fetal monitoring during labour. We have never investigated whether any form of fetal monitoring is better than not monitoring for example. We don’t know whether particular populations at extremely high risk for poor perinatal outcome might see benefits from the use of intrapartum CTG monitoring. Other than one trial which examined short and long term outcomes for women in preterm labour (Luthy et al., 1987; Shy et al., 1990), and another small trial looking at short term outcomes for women planning vaginal birth after caesarean section (Madaan & Trivedi, 2006) all the CTG trials in high-risk populations have included women with a mixture of different risk factors.
This makes it impossible to provide an evidence-based answer to questions such as:
- Will a woman who is being induced with prostaglandins and oxytocin have better outcomes if she has CTG monitoring rather than IA during labour?
- Will a woman who used IVF, has essential hypertension, and who has a growth restricted baby have better outcomes if she has CTG monitoring rather than IA during labour?
- Will a woman who has chosen to have epidural analgesia have better outcomes if she has CTG monitoring rather than IA during labour?
- Will a 43-year old woman with a high BMI and gestational diabetes have better outcomes if she has CTG monitoring rather than IA during labour?
Where does that leave us as clinicians?
There are two mind shifts that I think need to occur in relation to providing maternity care.
First, the goal of CTG monitoring is to reduce perinatal death or long-term neurological injury from hypoxia. There has been a collective narrowing of vision around the possible ways that we might go about achieving these goals. The focus has been on things that clinicians do once a woman has crossed the threshold of a maternity service, and particularly on expensive high-tech options. Many of the factors which modify the risk of perinatal harm relate to larger societal issues, like poverty, domestic abuse, and systemic racism. Any genuine attempt at improving perinatal outcomes must address these problems and that requires individual clinicians, health services, and professional organisations to become far more political and focused on social change than is the current position.
Second, we need better answers to our questions. There has been little progress in research regarding the use of CTG monitoring in the past 30 years, other than to try (without success) to show that a new high tech addition to the CTG, or a different approach to education will work. I believe this is related to the widespread misunderstanding that we have the answers we need already. Without an acknowledgement that we don’t know enough to provide sound clinical care, there will be no urgency to pursuing a research agenda. We either need to discard CTG monitoring, acknowledging that it has failed to live up to expectations, or re-engage with a research agenda to identify better ways to identify women who might benefit from intrapartum CTG monitoring and what that monitoring might look like.
We can’t expect individual birthing women and their care providers to figure out what is the right thing do. To continue on pretending that what we are doing is working, or would work if people just tried a little harder, is unethical. We need system wide change.
Luthy, D. A., Shy, K. K., van Belle, G., Larson, E. B., Hughes, J. P., Benedetti, T., Brown, Z. A., Effer, S., King, J. F., & Stenchever, M. A. (1987, May 01). A randomized trial of electronic fetal monitoring in preterm labor. Obstetrics & Gynecology, 69(5), 687-695.
Madaan, M., & Trivedi, S. S. (2006, Aug). Intrapartum electronic fetal monitoring vs. intermittent auscultation in postcesarean pregnancies. International Journal of Gynecology and Obstetrics, 94(2), 123-125. https://doi.org/10.1016/j.ijgo.2006.03.026
Shy, K. K., Luthy, D. A., Bennett, F. C., Whitfield, M., Larson, E. B., van Belle, G., Hughes, J. P., Wilson, J. A., & Stenchever, M. A. (1990, Mar 01). Effects of electronic fetal-heart-rate monitoring, as compared with periodic auscultation, on the neurologic development of premature infants. New England Journal of Medicine, 322(9), 588-593. https://doi.org/10.1056/NEJM199003013220904
- The story behind our paper
- The invention of the CTG machine: the history of fetal heart rate monitoring
Categories: Basics, CTG, EFM, Reflections
As I see it CTG is fundamentally flawed as it is measuring the stretch at one small area of the maternal abdomen which may or may not indicate that a contraction is happening and comparing it with an ultrasound approximation to the fetal heart. Electromyographic recording from more than one place on the maternal abdomen would be a better guide to contractions. Neither CTG or EHG can be a substitute for midwives’ mindful observations of contraction status and direct listening to the fetal heart via a Pinard stethoscope.
But for now CTG may be useful as a guide as to what is happening when no one is with the mother to record these things. It may also be useful for women who have an epidural in place and who may give no indication of when they are having a contraction. Maternal position may disrupt CTG recording leading caregivers to restrict women’s movement and yet freedom of movement is all important in efficient uterine function – and ability to alleviate, or act on pain signals.
I think that electromyography by telemetry may be the way to go – if They are quite determined to have a record of labour – but how much is the CTG printout for the benefit of the lawyers and the expert witnesses who can earn money arguing about the significance of it all?
It’s much better to make sure the woman has continuous support from a clinician, rather than a continuous CTG trace looked at intermittently.
I suspect that one reason obstetricians like it is because they find the graphs easier to read when they pop in intermittently than a midwife’s handwritten notes (and perhaps they don’t trust the midwives?) Sad, because midwives lose the skills of listening in and assessing contractions (something which obstetricians don’t get much chance to learn)
Absolutely agree, how high does the pile of research have to get before it is accepted that efm does not work, Cannot be accurately interpreted and damages for too many women and babies? But it is a boon for the lawyers.
It’s also a boon for organisations that run CTG education courses. Birthing women certainly aren’t benefiting from current practice.
Yes yes yes! This is so going into my book (full credit of course).
Thanks Kathryn! What’s your book going to be?
I love this post. There is so many research questions that have not been answered. So often we do research but ask the wrong questions before we begin. If only we had thought of more specific questions years ago. Some of them would be hard to answer now.
You are right – it would be close to impossible to get ethical approval for a trial of IA vs CTGs in premature labour. Yet we really need to know whether the 250% increase in cerebral palsy seen with CTG use is a consistent finding.