Clinical Outcomes After Recovered, Positive, and Negative Pulse Oximetry Screening Results Among Newborns

Importance Pulse oximetry screening (POS) detects critical congenital heart defects (CCHDs) and other neonatal morbidities, but the clinical significance of initially abnormal results that normalize on repeat testing remains unclear. Objective To assess the prevalence and clinical implications of positive, recovered, and negative early POS results in asymptomatic newborns. Design, Setting, and Participants This population-based cohort study included asymptomatic neonates born at 35 weeks’ gestation or later who underwent early POS at 2 to 6 hours of age at a tertiary-level university hospital in Eastern Finland between January 1, 2012, and December 31, 2019. Data were analyzed from August 2025 to August 2026. Exposure Positive POS result or indeterminate POS result that normalized to a negative POS result (recovered) with repeat testing. Main Outcomes and Measures Primary outcomes were neonatal intensive care unit (NICU) admission and continued hospitalization at 7 days; secondary outcomes included diagnostic investigations and neonatal morbidities. Associations between POS screening results and outcomes were examined using modified Poisson regression adjusted for maternal age, parity, body mass index, and cigarette smoking during pregnancy and newborn sex, gestational age, and birth weight Z score. Results The cohort included 16 599 newborns born at 35 weeks’ gestation or later who underwent early POS at 2 to 6 hours of age (8349 [50.3%] female; mean [SD] gestational age, 39.8 [1.3] weeks). POS results were negative in 16 160 newborns (97.4%), recovered in 208 (1.3%), and positive in 231 (1.4%). Compared with a negative POS result, a recovered or positive POS result was associated with higher risk of NICU admission (adjusted risk ratio [ARR], 5.62 [95% CI, 4.58-6.91] and 13.04 [95% CI, 11.77-14.44], respectively) and continued hospitalization at 7 days (ARR, 4.70 [95% CI, 3.07-7.19] and 11.97 [95% CI, 9.26-15.47], respectively). Recovered POS was also associated with greater risk of antibiotic exposure before 72 hours of life (ARR, 5.45 [95% CI, 3.94-7.52]) and need for respiratory support (ARR, 10.16 [3.53-29.21]) compared with a negative result. Respiratory disease was more common in newborns with recovered than negative POS results (27 [13.0%] vs 214 [1.3%]), as were sepsis (10 [4.8%] vs 127 [0.8%]) and hypoglycemia (17 [8.2%] vs 565 [3.5%]). No CCHD occurred among newborns with recovered POS. Conclusions and Relevance In this cohort study of neonates born at 35 weeks’ gestation or later, those with initially indeterminate POS results that normalized on repeat testing had increased risks of treatable neonatal conditions and hospital care but not of CCHD. Further prospective studies should investigate whether targeted assessment of these newborns could reduce morbidity and prolonged hospitalization.