Updated NICE Cardiotocograph (CTG) Guideline: Is it Suspicious or Pathological?

Abstract

Cardiotocograph (CTG) trace was introduced into clinical practice in 1960s as a tool to record the changes in the fetal heart rate (cardio) in response to ongoing uterine contractions (toco). The intention was to timely recognise the features of fetal decompensation so that immediate action could be taken to avoid hypoxic ischaemic encephalopathy (HIE) and/ or intrapartum hypoxia-related perinatal deaths, without increasing unnecessary operative interventions to the mother. However, very unfortunately, unlike other tools in clinical medicine, CTG was introduced into clinical practice without any randomised controlled trials or robust scientific studies not only to confirm its effectiveness, but to determine the CTG features which actually reflected fetal central organ oxygenation. This chasm of deficiency of knowledge of fetal physiology created a vacuum of understanding regarding what features were reflecting fetal compromise. Regrettably, this vacuum was soon filled by prominent obstetricians from national societies who were presumed to have the knowledge, but they began the arduous journey of classifying decelerations which are normal fetal cardioprotective reflexes, and they misclassified them as signs of “fetal distress”. Classification of these decelerations based on the observed morphology into “reassuring” and “nonreasoning” categories has resulted in disastrous consequences for women and babies. In the UK, since the publication of the first CTG guideline in 2001, due to continuing lack of knowledge and confusion, these guidelines were repetitively revised in 2007, 2014, 2017 and 2022. Despite the international consensus guidelines of physiological interpretation of CTG produced by 44 CTG experts from 14 countries which recommended classification of CTG traces based on the type of fetal hypoxia and fetal response to stress, the latest revised guideline produced by the National Institute of Health and Care Excellence (NICE), had continued the illogical approach of grouping arbitrary features into different categories and then randomly combining them to classify the CTG traces into “Normal, Suspicious and Pathological”. Therefore, all practising clinicians who are focussed on protecting their patients from harm have a responsibility to ask the question whether the revised NICE CTG Guideline itself is suspicious or pathological from a patient safety perspective.