Objective To evaluate the use of pulse oximetry as a screening tool for detecting major congenital heart defects (CHDs) in Indian newborns.

Design Cross-sectional observational study.

Patients In a community hospital of north India, babies born during a specific 8 h period of the day were recruited over a period of 3 years. Newborns with incomplete documentation were excluded.

Intervention Routine clinical examination, pulse oximetry and bedside echocardiography.

Outcome measures Any abnormalities in clinical examination and pulse oximetry were recorded. CHDs were diagnosed using bedside echocardiography. Accuracy of pulse oximetry, clinical examination and their combination for detecting major CHDs was calculated.

Results Among the 19 009 newborns screened, 70 had major CHDs at birth (44 serious, 26 critical). Pulse oximetry detected 39 major (sensitivity 55.7%, 95% CI 44.1% to 66.8%; specificity 68.3%, 67.6% to 68.9%) and 22 critical CHDs (sensitivity 84.6%, 66.5% to 93.9%; specificity 68.3%, 67.6% to 68.9%). Addition of pulse oximetry to clinical examination significantly improved sensitivity for major CHDs (35.7% (25.5% to 47.4%) to 75.7% (64.5% to 85.3%), p<0.01) and critical CHDs (11.5% (4.0% to 29.0%) to 84.6% (66.5% to 93.9%), p<0.01).

Conclusions Pulse oximetry is a sensitive screening tool for detecting major CHDs in Indian newborns. It adds significant value to the current practice of using clinical examination as a sole screening tool for detecting major CHDs. However, specificity of pulse oximetry was much lower in our study. Possible reasons for low specificity could be non-repetition of pulse oximetry in newborns with initial lower saturations, high prevalence of infections and respiratory issues in our cohort and use of non-motion tolerant oximeter.