CG190 Fetal monitoring in labour (CTG)

My second CG190 blog on monitoring the fetal heart rate – this time focusing on CTG use and trace interpretation. What is the evidence, and what is new and different about these recommendations? (Please do also read my previous post to understand this summary in context.) Again, I am assuming a basic familiarity with the evidence.

While writing this post, I have come across this fabulous resource of which I was unaware!  Here on NCBI is a fully interactive version of Chapter 10 including Appendix P (all the Appendices are there!) Recommendations below are from the NICE online version and the Full guideline is here (with Appendices) on the NICE website, along with pathways, and the Quality Standard.

Note that significant sections of the CG190 fetal monitoring recommendations have been brought within the scope of the Intrapartum Care guideline for women at higher risk of complications currently being developed – see link below  (under ‘Resources’) for full details. See introduction to my previous post too.

(28 May 2016, published 5 June 2016)

Continuous monitoring of the fetal heart

In my previous post I noted that CTG is a screening test. Also, a CTG machine does not provide a diagnosis if it suggests a reason to check that all is well in the labour, nor does the machine provide care to the woman.

Unfortunately, women are sometimes left alone when a CTG monitor is being used – they don’t have a healthcare professional with them all the time. This happens despite evidence-based CG190 recommendation 1.7.1.  Given that a CTG machine is screening for possible problems in a labour that either began or has become at higher risk of complications, this clearly makes no sense. This is reflected in recommendations 1.10.10-1.10.12 (Full guideline recommendations 107 onwards):

recs 1.10.10 - 1.10.12 fhr tell wmn, not ctg alone

This is some of the context for the recommendations. How were those recommendations made?

Interpreting the best available evidence

What was the evidence (in 2014) and what was the ‘systematic review’ question (for labours that begin at low risk of complications, and then become at higher risk)? Turning now to the Full guideline:

EFM FHR p425 introduction to topic

Stay with this, because it is interesting reading. Here the Full guideline prepares to take us through the evidence:

EFM FHR p426 reporting parameters GRADE

For a visual representation of predictive accuracy, it is worth looking at the ‘traffic light diagrams’ (my phrase for remembering that they are red-yellow-green for not useful-moderately useful- very useful in Appendix P. Here is an example, with the Appendix P explanatory note below it:

Appendix P variable decelerationsAppendix P explaniner

Appendix P contains visual representations of the evidence in this form for all key features of traces, and for fetal heart rate patterns too. It is well worth a look.

Here is the evidence summarised in words, for those who prefer that – stay with it because the answer to ‘how were the recommendations made – and why do they say what they do?’ is here:

EFM FHR p481 Evidence statements a.png

EFM FHR p482 Evidence statements bEFM FHR p483 Evidence statements cEFM FHR p484 Evidence statements dEFM FHR p485 Evidence statements e

Did you catch that? Here is a key section again – this is what I found surprising and challenging, given my prior assumptions about this technology and its use in high risk labours. I had assumed that the evidence would clearly support current clinical practice:

“CTG has a good negative likelihood ratio; that is, when it is normal there is a very low chance of hypoxia (and therefore acidosis). However, evidence from this review showed that the use of CTG is only moderately useful at best in predicting poor fetal/neonatal outcomes, with the majority of studies showing it to be not useful (not useful positive likelihood ratios). In addition, there are randomised studies (see section 10.1), albeit underpowered, which fail to show that the use of CTG in practice improves neonatal outcomes in a clinically significant way. There is some evidence supporting the usefulness of these features of CTG in predicting neonatal outcome or the surrogate measure of low umbilical cord blood pH: [see list in extract above]”

Keep going – there is more analysis coming up (and you will note that there was very little evidence relating to high risk labours in 2014):

EFM FHR p485 next - considering Ev & making RecsEFM FHR p486 making the recs

Then comes the business of deciding how to reflect the evidence in the updated recommendations. Stay with it. As I like to say when I give talks, we didn’t make it up: here is part of the summary of the evidence from the systematic review:

EFM FHR p487 making the recs

And so on – evidence about decelerations and patterns/combinations was interpreted as explained in the remainder of Full guideline section 1.3.10.5.

All of the work  on this topic by the GDG (many days, and significant input from the topic group, drawn from the GDG, that worked virtually to refine draft wording, for the full group to discuss and settle, ready for the public consultation) led to some key conclusions:

EFM FHR p488 Key conclusions aEFM FHR p489 Key conclusions b.png

and the recommendations that are summarised in the tables here (see ‘interpretation of cardiotocograph traces table’) (which were refined following public consultation) or this link to the same Tables 10 and 11 (at 1.10.9 here).

What was important about the 2014 recommendations?

The key thing about the recommendations in the tables? They take the updated 2007 recommendations (being updated in 2014 for women at low risk of complications in pregnancy, for whom a risk of complications is identified at the beginning of or during labour) closer to the evidence for this population. It was evidence that surprised me, when I engaged with the detail. When I speak about ‘doing the science properly’ in doing the CG190 2014 update, I mean all of it – and I have all of chapter 10, this section especially, and chapter 3 (planning place of birth) at the forefront of my mind.

Appendix P is something to reflect on – to be looked at with the ‘Evidence to Recommendations’ section in chapter 10 that is about interpretation of the fetal heart rate when a CTG machine is used.

The recommendations about interpreting CTG traces remind clinicians that monitoring is a screening test. That interpretation of the results and ongoing care are essential. That the labouring woman, not technology, must be at the centre of care.

This is arguably a complex topic evidence-wise. In another way, it is very straightforward. Universal implementation of an intervention that has not been properly researched and is not fully understood, to the point that forgoing use of it is deemed ‘not ethical’ despite the lack of research, is not something one would ever want to see again in maternity. These are more enlightened times, one hopes, than the 1970s.

The GDG selected two of the monitoring recommendations for the list of key priorities for implementation. Two of the recommendations are used as the basis of Quality statements in the Quality Standard, made a by a different NICE panel (including two topic experts from the CG190 GDG.)

After reading this, don’t forget to check via the link below (see ‘Resources’) for the up to date 2016/17 position in relation to CG190 and ‘IPC2’, but I hope this has been interesting.

Other fetal monitoring topics in CG190

There are sections of Full guideline Chapter 10 on monitoring when there is meconium-stained liquor; fetal scalp stimulation; fetal blood sampling; women’s views and experiences of monitoring; electrocardiogram analysis; computerised systems; record keeping and risk management. But enough on monitoring for now. My next CG190 post will be about the recommendations about caring for the women in the third stage of labour, including timing of clamping of the umbilical cord.

Note: the recommendations as published by NICE are numbered differently from those in the Full guideline published by the National Collaborating Centre for Women’s and Children’s Health (as it was in 2014; nowNational Guideline Alliance.) The page numbers in my printed copy of the Full guideline (yes, I had a local print shop print and bind one for me!) don’t match those that appear in my pdf reader. So apologies for any difficulties you have following references. Best to use the contents list in whichever version you are looking at. 

Resources

NICE CG190 on the US National Center for Biotechnology Information website – a fully interactive online version of the Full guideline:

http://www.ncbi.nlm.nih.gov/books/NBK290736/

The NICE ‘guidance in development’ project documents for intrapartum care for women at higher risk of complications – see ‘Addendum to scope’ (which covers intrapartum monitoring of the fetal heart rate), and note the stakeholder comments on the Addendum too (both published 2 June 2016):

https://www.nice.org.uk/guidance/indevelopment/gid-cgwave0613/documents

Note that all NICE clinical guidelines are available on the NCBI site:

http://www.ncbi.nlm.nih.gov/books/NBK11822/

 

 

 

 

 

 

 

 

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