All newborn babies should be routinely screened for life-threatening heart defects using a simple and painless test, researchers have said.
The pulse oximetry test measures blood oxygen levels in newborns by means of a small skin sensor placed on the hands or feet.
A major British study published today 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.
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% and no babies died from undiagnosed problems.
The findings were published today in an online edition of The Lancet medical journal.