A quick and inexpensive test could save the lives of babies born with congenital heart defects, British doctors say.Researchers said a study of 20,055 newborns showed testing oxygen in the blood was more successful than other checks available for such defects such as ultrasound during pregnancy or by listening to the heart after birth, BBC News reported Friday.Doctors at six British maternity hospitals used pulse oximeters -- a technology that has been available for 20 years -- to detect levels of oxygen in the blood.If oxygen levels were found to be too low, more detailed examinations took place. The test takes less than 5 minutes and it gave warning of 75 percent of the most serious abnormalities, the researchers said.Dr. Andrew Ewer, the lead researcher at the University of Birmingham, called for the test to be adopted by hospitals across Britain.\"It adds value to existing screening procedures and is likely to be useful for identification of cases of critical congenital heart defects,\" he said.