I want to share details of two papers today which I have been quoting in my workshops and talks for a while now but which have just this month been published in the print version of the BJOG. Both concern fetal monitoring in labour, both are written by obstetricians at the same London Trust (St Georges) and both add further weight to the notion that we should be thinking very hard about what we are doing in this area.
I can’t provide a better summary of the first paper than to share the title and the abstract that the author himself provides:
Are we (mis)guided by current guidelines on intrapartum fetal heart rate monitoring? Case for a more physiological approach to interpretation.
“Original interpretations of fetal heart rate (FHR) patterns equated FHR decelerations with ‘fetal distress’, requiring expeditious delivery. This simplistic interpretation is still implied in our clinical guidelines despite 40 years of increasing understanding of the behaviour and regulation of the fetal cardiovascular system during labour. The physiological basis of FHR responses and adaptations to oxygen deprivation is de-emphasised, whilst generations of obstetricians and midwives are trained to focus on, and classify, the morphological appearances of decelerations into descriptive categories, with no attempt to understand how the fetus defends itself and compensates for intrapartum hypoxic ischaemic insults, or the patterns that suggest progressive loss of compensation. Consequently, there is a lack of confidence, marked variation in FHR interpretation, defensive practices, unnecessary operative interventions, and a failure to recognise abnormal FHR patterns, resulting in adverse outcomes and expensive litigation.” (Ugwumadu 2014: 1063)
This paper is detailed and, while it unfortunately wasn’t freely available at the time of posting, it makes for really interesting reading if you can get hold of it. Ugwumadu (2014) challenges current guidance, offers alternatives and provides much food for thought and debate. His response to the use of the ‘DR C BRAVADO’ mnemonic which is designed to aid in the assessment of CTG tracings is that, “The user is compelled to document their assessment of the CTG features by ticking relevant boxes, but no reference is made to the evolution or progression of the FHR, the success or failure of fetal compensation, or the potential fetal consequences. Some clinicians regard this ‘tick box’ exercise as the object of FHR interpretation.” (Ugwumadu 2014: 1064)
This is one of a number of areas where our understanding of physiology has grown without widespread and concomitant consideration of how our changed knowledge might be applied to practice. While it only relates to part of the bigger question of what kinds of fetal monitoring we should be offering to women in labour, it is a welcome addition to the literature on a topic that affects so many women and babies.
The second paper is equally clearly titled: Fetal scalp blood sampling during labour: is it a useful diagnostic test or a historical test that no longer has a place in modern clinical obstetrics?
In this paper, Chandraharan (2014) unpacks the history of and evidence relating to fetal scalp blood sampling, and I was fascinated to read some of this:
“Contrary to the popular belief in the UK, FSBS did not develop as an additional test of fetal wellbeing to reduce the false-positive rate of CTG. FSBS developed as a test of fetal wellbeing in its own right, used by Saling in Berlin, Germany in 1962, before commercial production of CTG machines in 1968. He took scalp blood samples from babies during labour to detect acidosis and published his series. This test, which was then developed as an alternative to CTG, was subsequently introduced in the UK, when CTG was found to have a high false-positive rate, to reduce unnecessary operative interventions.” (1056).
Probably my favourite line from this paper, and certainly the one I have most often quoted is this one:
“Current normal and abnormal values for fetal scalp pH that were recommended by the NICE Guideline Development Group on Fetal Monitoring were derived from two small studies that were performed in 1962 and 1968, without sound scientific basis.” (Chandraharan 2014: 1056)
This happens so often, and in so many areas, and it’s hard to spot where it is going on unless you have the time, skills and energy to take a deep look into the background of a subject. Which is why it’s so great when colleagues take the time to write articles like these ones.
Chandraharan E (2014). Fetal scalp blood sampling during labour: is it a useful diagnostic test or a historical test that no longer has a place in modern clinical obstetrics? BJOG: An International Journal of Obstetrics & Gynaecology 121(9): 1056–62.
Ugwumadu A (2014). Are we (mis)guided by current guidelines on intrapartum fetal heart rate monitoring? Case for a more physiological approach to interpretation. BJOG: An International Journal of Obstetrics and Gynaecology, 121(9):1063-70.