Interpretation
The underlying goal of physiology-based CTG interpretation is to
dispense with second-line methods14,15. In a 2014
insightful review, Edwin Chandraharan pointed out the absence of
evidence supporting foetal scalp blood sampling during
labour13. This critique was brilliantly enriched with
a detailed list of pathophysiological inconsistencies associated with
the use of this test; in particular, a sample of blood from nonessential
peripheral tissue (foetal scalp) is being used to assess the acid–base
status of essential central organs. His conclusion was that foetal scalp
blood sampling was an outdated practice and that it should no longer be
recommended. This review provoked a debate among various authors whose
responses were just as interesting as the original article, essentially
discussing the pathophysiological basis of foetal scalp blood
sampling16–18. These expert debates are enlightening,
but no pathophysiological analysis can ever replace the evidence
provided by a well-conducted clinical study. Since 2014, despite this
article, which should have encouraged research on this matter, little
has been done to demonstrate the usefulness of second-line methods,
which are still widely used despite this lack of evidence.
The same reasoning could easily be applied to physiology-based CTG
interpretation training. There is no doubt that pathophysiological
teaching leads to a deeper understanding of medical phenomena and should
be encouraged. Recent studies showed that training programmes based on
foetal physiology led to a long-term improvement in CTG interpretation
and to homogenization of obstetrical decisions in simulated
situations19,20. However, there is a strong need for
clinical evidence regarding the teaching of this method before totally
discouraging second-line methods. As suggested by our results,
overconfidence in the interpretation of CTG could lead to wrong
decisions and it should therefore be taught with humility and by
stressing the importance of being cautious when in doubt. The present
article is up to date and, to our knowledge, is the only attempt to
analyse the effect of physiology-based CTG interpretation training on
obstetrical practice. Although our work is clearly insufficient on its
own to substantiate the benefits or shortcomings of this teaching, it
does have the merits of raising the issue of the lack of evidence and
should encourage further research.