Simple blood oxygen test identifies newborns with dangerous heart defects

13 August 2011

A simple test to measure blood oxygen in newborns has been shown to identify babies with life-threatening congenital heart defects, a major cause of infant mortality in the developed world.

The PulseOx study, conducted by researchers from the University of Birmingham and Birmingham Women’s Hospital, was the largest UK investigation into screening newborns for congenital heart defects, which occur in 1 in 160 births in the UK. The results have been published in The Lancet [1].

More than 20,000 mothers and babies from throughout the West Midlands took part in the trial. Midwives used pulse oximetry to measure oxygen levels in newborns’ blood via a small sensor placed on the skin of hands or feet. Babies with low oxygen levels soon after birth may be at increased risk of heart defects.

Current screening for heart defects involves ultrasound before delivery and routinely examining all newborns in the first 24 hours after birth. However these examinations often miss babies with serious heart defects. PulseOx is an additional test which is carried out on the postnatal ward, before discharge from hospital and can be life-saving.

Babies who failed the PulseOx test were given a heart ultrasound. Of 195 babies with an abnormal result following the test, 26 had a major congenital heart defect and a further 46 had other important problems which required urgent treatment brought to attention by the test.

‘It’s usually performed within 24 hours of birth and is simple, painless and non-invasive,’ explains lead investigator Dr Andrew Ewer. ‘A small probe is put on the baby’s hand and then on the foot, the machine is switched on and you obtain a reading. That’s it. It takes longer to undress the baby than it does to do the test.

‘This study has shown conclusively that this test is advantageous,’ he goes on. ‘We would like to see all babies being routinely tested. In this way the test will pick up additional babies who might otherwise have become very ill or even died. I think we now have enough evidence to say that pulse oximetry screening should be incorporated into everyday clinical practice.’

The research was carried out in six NHS trusts: Birmingham Women’s Hospital, Heart of England NHS Foundation Trust, City Hospital (Sandwell and West Birmingham NHS Trust.), New Cross Hospital (the Royal Wolverhampton Hospitals NHS Trust); Royal Shrewsbury Hospital (the Shrewsbury and Telford Hospitals NHS Trust); University Hospital of Coventry and Warwickshire.

Reference

1. AK Ewer, et al. Pulse oximetry screening for congenital heart defects in newborn infants (PulseOx): a test accuracy study. The Lancet, Early Online Publication, 5 August 2011. doi:10.1016/S0140-6736(11)60753-8