Fetal monitoring and cherry picking evidence…

Cherry picking evidence? Really?!

Two senior doctors have written to the British Medical Journal to commend them for publishing a recent debate which highlights the way “in which the doctors supporting monitoring seem to cherry pick evidence” (Bewley and Braillon 2018). During this debate, Peter Brocklehurst, the “principal investigator of many great obstetric trials (including INFANT, a randomised controlled trial of 47 062 women undergoing continuous electronic fetal heart rate monitoring)” (Bewley and Braillon 2018) explained that,

“As a screening test, electronic fetal monitoring performs poorly. It has a poor positive predictive value, even with computerised interpretation of the fetal heart rate. This means that most of the fetuses identified as being at risk of hypoxia are not.” (Brocklehurst 2017).

In their letter, Bewley and Braillon (2018) point out that “Cochrane, the International Federation of Gynecology and Obstetrics, and the National Institute for Health and Care Excellence have all said that no evidence shows that human or computerised interpretation of cardiotocographs reduces the rates of intrapartum stillbirth and cerebral palsy but does cause maternal harm. INFANT showed that adding intelligent decision support to costly and demanding cardiotocography did not improve clinical outcomes for mothers or babies.”

They offer suggestions of other approaches to screening for and dealing with fetal hypoxia: mobile resuscitation devices which enable resuscitation to be carried out without cutting the cord, and carbon monoxide breath ananlysers. While the latter may raise ethical and wider issues which need careful consideration (as has been raised by some of the people involved in human rights and childbirth groups), it is clear that we need to reconsider this technology, which has failed to live up to our hopes.

Such reconsideration will not only involve challenging beliefs. Bewley and Braillon (2018) conclude that, “Our longstanding reliance on cardiotocography shows the effect of a rigid mindset but might be related to vested interests from equipment manufacturers, plaintiff lawyers, and experts with lucrative medicolegal practices.”


See all our fetal monitoring information here:

Fetal monitoring research resources


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Bewley S and Braillon A (2018). Electronic fetal heart rate monitoring: we need new research approaches. BMJ 2018: 360: k658.
Mullins E, Lee C and Brocklehurst P (2017). Is continuous electronic fetal monitoring useful for all women in labour? BMJ 2017: 359: j5423.
photo credit: fetal monitor by ahhyeah

5 comments for “Fetal monitoring and cherry picking evidence…

  1. February 19, 2018 at 7:27 pm

    “They offer suggestions of other approaches to screening for and dealing with fetal hypoxia: mobile resuscitation devices which enable resuscitation to be carried out without cutting the cord…” Yes! Please!

  2. Juliet Hitchiner
    December 17, 2018 at 8:25 pm

    At last this has come to the surface again CTGs have been the bane of my life as a midwife for years!

  3. Clare
    December 17, 2018 at 10:34 pm

    Is this in all cases, or just low risk pregnancy/birth? What about induction? Epidural?

  4. Sarah
    July 21, 2019 at 9:27 pm

    Completely anecdotal, but just this week I went to my 41 week appointment with my OBGYN (in the US) during which I had electronic fetal monitoring and an ultrasound done, followed by another, more comprehensive CTG test done at the L&D unit of the hospital just across the street.

    The first reading (in OBGYN’s office) showed a baseline of 110-115 with “great accelerations”, but was entered into my record as “fetal bradychardia”. The ultrasound immediately followed the CTG (by mere minutes) and was done mostly to check amniotic fluid, but the person performing it commented, “hmm, now her heart rate is showing as 133. What are you doing in there, little one?” While I was told everything looked generally great, my results weren’t “A+”, so I was sent to L&D where apparently more thorough monitoring could be done. I arrived at L&D and probably within 20 minutes I was hooked up to the machine, plus another 20 minutes of monitoring and this time the baseline reading showed 120-125, again with great accelerations.

    I realize many things could be influencing these readings, and someone please chime in if you have insight as to what might be going on here, but in the span of a few hours this seems a bit variable to me to say the least. Considering that these machines are used to inform whether “fetal distress” is occurring, and that decisions could be made about intervening based on these numbers, shouldn’t we be hoping for a system that’s a bit more reliable?

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