Scientists advocate lifesaving heart tests for babies

Researchers from the University of Birmingham have reported that the pulse oximetry test measures blood oxygen levels in newborns by means of a small skin sensor placed on the hands or feet.

Their major UK study published in The Lancet this week showed it can identify babies with congenital heart defects who would otherwise be missed by doctors.

Many of these infants would under normal circumstances go on to develop serious complications or die.

Identifying the problems early on allows doctors to correct or reduce them with surgery, where possible, or plan medication treatments.

Heart defects present from birth are one of the leading causes of infant death in the developed world and affect one in 145 newborn babies in the UK.

Examples include hypoplasia, or underdevelopment of part of the heart, obstructions that block blood flow, valve defects and hole-in-the-heart conditions that allow blood to leak from one side of the heart to the other.

Current techniques for identifying babies with a congenital heart defect involve ultrasound scans and routine physical examinations shortly after birth.

However these methods are far from foolproof and many affected babies leave hospital undiagnosed.

The new study, the largest of its kind ever undertaken in the UK, tested the accuracy of pulse oximetry on more than 20,000 babies born at six maternity units across the West Midlands.

In all cases the babies appeared to be healthy at birth.

The tests, conducted between February 2008 and January 2009, detected 53 cases of major congenital heart disease, 24 of which were critical.

In 35 cases, congenital heart defects were already suspected after ultrasound examinations. But 18 cases identified by pulse oximetry had not been picked up by ultrasound.

The test was able to spot three quarters of all critical cases. When it was combined with ultrasound and physical examination, the detection rate of critical heart abnormalities rose to 92 per cent and no babies died from undiagnosed problems.

Describing the test, lead investigator Dr Andrew Ewer said: “It’s usually performed within 24 hours of birth and is simple, painless and non-invasive.

“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.”

He added: “This study has shown conclusively that this test is advantageous. 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.”