The study by Ewer et al. (2011) evaluates the accuracy of pulse oximetry as a screening test for congenital heart defects (CHD) in newborn infants. The study, conducted in six UK maternity units, screened 20,055 asymptomatic newborns using pulse oximetry before discharge. Infants who did not meet predetermined oxygen saturation thresholds underwent echocardiography, while others were followed up to 12 months. The main outcomes were the sensitivity and specificity of pulse oximetry for detecting critical CHD (causing death or requiring intervention before 28 days) and major CHD (causing death or requiring intervention within 12 months). The sensitivity of pulse oximetry was 75% for critical cases and 49.06% for all major defects. After excluding cases already suspected from antenatal ultrasonography, the sensitivity further decreased to 58.33% for critical cases and 28.57% for major defects. The specificity was 99.16%, with 169 false positives (0.8%). The study concludes that pulse oximetry is a safe and feasible test that adds value to existing screening methods, particularly in identifying critical CHD cases that may be missed by antenatal ultrasonography. The perspective highlights the importance of timely detection of major life-threatening CHD in newborns. The study supports the routine use of pulse oximetry, but notes that its sensitivity, ranging from 50% to 80%, may not be sufficient for screening potentially fatal defects. Additional costs and the need for proper implementation, especially in developing countries like India, are also discussed. Proper use of pulse oximetry, preferably with a plethysmograph, is emphasized to ensure accurate results.The study by Ewer et al. (2011) evaluates the accuracy of pulse oximetry as a screening test for congenital heart defects (CHD) in newborn infants. The study, conducted in six UK maternity units, screened 20,055 asymptomatic newborns using pulse oximetry before discharge. Infants who did not meet predetermined oxygen saturation thresholds underwent echocardiography, while others were followed up to 12 months. The main outcomes were the sensitivity and specificity of pulse oximetry for detecting critical CHD (causing death or requiring intervention before 28 days) and major CHD (causing death or requiring intervention within 12 months). The sensitivity of pulse oximetry was 75% for critical cases and 49.06% for all major defects. After excluding cases already suspected from antenatal ultrasonography, the sensitivity further decreased to 58.33% for critical cases and 28.57% for major defects. The specificity was 99.16%, with 169 false positives (0.8%). The study concludes that pulse oximetry is a safe and feasible test that adds value to existing screening methods, particularly in identifying critical CHD cases that may be missed by antenatal ultrasonography. The perspective highlights the importance of timely detection of major life-threatening CHD in newborns. The study supports the routine use of pulse oximetry, but notes that its sensitivity, ranging from 50% to 80%, may not be sufficient for screening potentially fatal defects. Additional costs and the need for proper implementation, especially in developing countries like India, are also discussed. Proper use of pulse oximetry, preferably with a plethysmograph, is emphasized to ensure accurate results.