Oxford Centre for Fetal Monitoring Technologies

 

The Oxford Centre for Fetal Monitoring Technologies was born in the early 2012 as a natural umbrella for the relevant work in the Nuffield Department of Obstetrics and Gynaecology spanning over 30 years. In recent years, after the attraction of Dr. Antoniya Georgieva to the team, there have been substantial developments in our work on intrapartum fetal monitoring (more information below). In parallel, there has been major further work by Ms. Mary Moulden and team on the update of the Oxford Dawes Redman antepartum system (more information below). We are also interested in the development of modern noninvasive acquisition devices that will make fetal monitoring less intrusive and disturbing to women and improve signal quality.

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Observation of the fetal heart rate is the core of standard fetal monitoring both prior to and during labour. The beating of the baby's heart is displayed on a continuous paper strip, showing a graph that changes through time (time-series). Any contractions are also detected and displayed on a separate concurrent graph. In labour, the responce of the fetal heart rate to contractions is of particular importance.

Monitoring during labour (Intrapartum)

During birth, the stress of contractions and descent through the birth canal can reduce a baby’s oxygen supply. Most babies have the resilience to cope but 2% suffer birth asphyxia (suffocation)[1], of which, 250 babies in the UK die each year [2]. Those who survive asphyxia may suffer convulsions and permanent brain damage. Therefore, such babies must be rescued by urgent delivery. To diagnose fetal distress and prevent birth asphyxia, the baby’s heart beat is electronically recorded during labour on a paper strip (Cardiotocogram, CTG). The complicated patterns are assessed by eye, which is error-prone and unreliable. Even experts disagree with each other or with themselves when reviewing the same trace at different times. Such uncertainty causes ‘fail-safe’ decisions and many unneeded Caesarean sections.

We will design a new diagnostic system, using objective computer analysis to assist interpretation of the labour CTGs. We have saved the electronic CTGs of nearly 30,000 babies with relevant clinical details. We can now study fetal distress or birth asphyxia in relation to the baby’s CTGs and grade the associated risks by statistical analysis. Although this analysis is complex, because CTGs change as labour advances or with events such as epidural use, the unique size of our database makes the analysis very powerful.

Our system will identify the CTG patterns that matter most for the baby. The labour experiences of nearly 30,000 women will be distilled into the memory of a computerised system to aid recognition of impending asphyxia, at the bedside. Such a system does not yet exist.

This system for intrapartum CTG analysis will be built upon its antepartum analogue - System 8000, developed in Oxford earlier by Prof Dawes and Prof Redman in the 1980-90s and produced by our industrial partner Huntleigh Healthcare.

[1] Levene and Chervenak, Fetal and Neonatal Neurology and Neurosurgery, 4th edition, 2009, pp506-527
[2] CMACE, Perinatal Mortality 2008, London 2010.

Monitoring before labour (Antepartum)
Electronic fetal heart rate monitoring was introduced in 1966 for use in labour. The technique was then successfully applied to monitoring the distressed fetus before labour. It was quickly appreciated that it generated errors due to the unstandardised process of visual assessment of complex patterns. This led to the development of the Oxford Dawes Redman computerised system for objective numerical recognition of important abnormal features. It is now marketed by Huntleigh Healthcare as Sonicaid FetalCare and Sonicaid Team. The system has been developed and validated on a large archive of antenatal traces linked to clinical outcome data. The system is constantly upgraded and a new version is planned for release in 2013-14.

Pardey J, Moulden M, Redman CW. A computer system for the numerical analysis of nonstress tests. Am J Obstet Gynecol 2002;186:1095-1103

The CTG is displayed on a paper strip