Screening heart disease in newborn babies

Close up graphic of a foetus with umbilical chord 

Lead investigator: Andrew Ewer

Introduction

Critical congenital heart defects occur in around two in 1,000 babies, and are a leading cause of infant death. A quick diagnosis is crucial for the best outcome for these children, but current methods only identify 35-50% of affected babies before birth, and those sent home before diagnosis may become unwell or die. Low blood oxygen levels can, however, be non-invasively detected by pulse oximetry, a simple sensor placed on newborn babies.

In 2007, Dr Andrew Ewer led the PulseOx study, assessing the accuracy of this technique for screening critical congenital heart defects in newborn babies. The study demonstrated the value of pulse oximetry in terms of accuracy, cost-effectiveness and acceptability to patients, resulting in 92% of babies with defects being detected prior to discharge. The work has had major impacts on international policy and practice, as well as for affected children and their parents.

The research was described in a Lancet editorial as 'a new milestone in the history of congenital heart disease'. A senior US cardiologist overseeing national regulations stated that the study ‘tipped the balance of evidence towards universal screening in the USA’. Many other countries are now actively considering its regular usage in clinical practice, including the UK.

Dr Andrew Ewer is a Reader in Neonatal Paediatrics at the University of Birmingham since 1995.  He recently led the PulseOx trial investigating pulse oximetry as a screening test for congenital heart defects in newborn babies.

The PulseOx study was recently featured in a Medical School’s Council report about the impact of the UK’s Medical Schools research.  The trial was featured as a piece of world leading UK medical research, which reinforces the importance and prominence of this study.

See the report (page 7) Health of the Nation: The impact of UK medical schools' research [pdf]

In the video below, Andy Ewer discusses this research and its impact.

Screening heart disease in newborn babies

Research objectives

Congenital heart defects are a leading cause of infant death, accounting for more deaths than any other type of malformation and up to 7.5% of all infant deaths.

Critical congenital heart defects (CCHD) occur in around 2 in 1000 babies, and are most likely to cause death. If they are not detected early, risk of circulatory collapse is increased, and although surgery can greatly improve survival, a quick diagnosis is crucial for the best outcome for these children. However, the accuracy of current methods for detecting CCHD is variable and only 35-50% of affected babies are identified before birth. Defects may be identified after birth, however around a third of babies with these potentially life-threatening defects in their hearts are sent home before diagnosis, where they may become unwell or die.

Blood oxygen levels are often low in CCHD. Pulse oximetry is a non-invasive method of measuring blood oxygen levels by placing a sensor on part of the patient’s body. Although the technique itself was developed in the 1980s, and explored for CCHD identification in the 2000s, the results were inconclusive.

Research output

2007, Dr Ewer led the PulseOx study, a large study which assessed the accuracy of pulse oximetry for screening CCHDs in newborn babies.

It was the largest UK study in this field, screening 20,055 newborn babies, and the first to assess the added value of pulse oximetry screening in modern healthcare systems where antenatal ultrasound screening was widely available.

The study used robust methodology to generate precise estimates of the accuracy, cost-effectiveness and acceptability of pulse oximetry and the value added to existing screening. These results demonstrated that the addition of pulse oximetry screening to existing screening tests resulted in 92% of babies with CCHDs being detected prior to discharge.

The results of this study significantly enhanced available evidence indicating that pulse oximetry screening could be introduced as a routine procedure.

Dr Ewer’s team also assessed the cost-effectiveness of utilising pulse oximetry screening in combination with clinical examination in the early detection of potentially life-threatening CCHDs. They demonstrated that the technique would identify 30 additional CCHD cases per 100,000 live births compared with routine clinical examination alone, and therefore would be worth the extra investment. 

Research impact

Through a portfolio of clinical and theoretical studies, Dr Ewer’s work has provided extensive evidence of the clear benefits of pulse oximetry screening, and this has had major impacts on international policy and practice, as well as directly for children and their parents where the test has been implemented as a result.

Since Dr Ewer’s research, there has been a significant increase in the number of UK neonatal units undertaking routine pulse oximetry screening.

In units which were not screening, 70% were actively considering it, clearly indicating a nationwide shift of opinion among UK neonatologists about pulse oximetry screening in their local units, with a substantial majority now in favour.

A key ongoing impact of this work has been its use by lobbying groups, who have been very quick to recognise the benefits of pulse oximetry for screening newborns and are campaigning for its routine use in national practice.

Learn more

If you are interested in the work that Dr Ewer undertook in this area you can learn more by reading the published research. 

If this has sparked an interest in studying a course in the College of Medicine and Health, you can find a list of the of Undergraduate, Postgraduate and Doctoral research opportunities on offer from the College: