Cardiotocography alone is outdated and ST analysis is the way forward in fetal monitoring: AGAINST: An opportunity to avoid past mistakes in fetal monitoring

Abstract

Continuous electronic fetal heart rate monitoring is standard care in many regions, despite a lack of evidence that it reduces adverse neurodevelopmental sequelae, including hypoxic-ischaemic neonatal encephalopathy and cerebral palsy. It has a high false-positive rate, poor inter- and intra-observer reliability, and increases the operative delivery rate: surprising characteristics for a test in widespread use. Current risk stratification systems for intrapartum fetal heart rate monitoring are limited by indeterminate categories, where fetal status and perinatal outcome cannot be reliably predicted. The use of an adjunctive test to adjudicate indeterminate heart rate tracings has therefore been highly sought, and the use of fetal electrocardiogram (ECG) ST-segment analysis (ST analysis) has been evaluated in six randomised trials and several meta-analyses for this purpose. Initial trials conducted in Europe suggested that ST analysis reduced operative delivery, acidaemia, and neonatal encephalopathy. Subsequent trials have had conflicting findings. In 2015, a US randomised trial was published demonstrating that ST analysis did not improve composite perinatal outcome, nor decrease the rate of operative vaginal delivery or caesarean delivery (Belfort et al. N Engl J Med 2015;373:632–41). The most recent meta-analysis demonstrated no differences in the most meaningful outcomes, including caesarean delivery, severe acidaemia at birth, or neonatal encephalopathy (Neilson Cochrane Database Syst Rev 2015;12:CD000116). Fewer scalp blood samples and marginally fewer operative vaginal deliveries have been demonstrated: outcomes of dubious importance when considering the overarching intent to prevent adverse neonatal outcomes and unnecessary caesarean deliveries. Indeed, these positive outcomes are even less relevant in settings where fetal scalp sampling is uncommon, like the US. The summative literature therefore suggests that adjunctive ST analysis does not meaningfully and consistently modify intrapartum and neonatal outcomes. The biological basis of fetal ST analysis is compelling; however, its success depends on correct interpretation and appropriate intervention (or non-intervention). It remains as susceptible to human fallibility as traditional fetal heart rate monitoring. There is a learning curve seen within published clinical trials, and intense education and training may improve test performance; however, if meaningful outcome differences cannot be demonstrated in large randomised trials, we have no hope of seeing a positive effect in daily practice, where education and oversight may be less than ideal. A promising technology and the hope of finally having an effective intrapartum monitoring tool should not blind us to the fact that our collective investment as a scientific community in ST analysis has not paid off, and is unlikely to do so in the future. The debate about fetal ST analysis and its potential usefulness has not ended. But, perhaps it should. Do we as a society, who must be conscientious of cost-effectiveness and value in health care, want to continue to invest in ST analysis for the minimal demonstrated benefit? We have a new opportunity to decline to use a technology that does not improve neonatal outcomes, nor reduce the rate of caesarean delivery, and in the process save considerable time and money that might be better spent developing effective prevention and intervention strategies for mothers and their babies. None declared. Completed disclosure of interests form available to view online as supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.