Introduction: Despite disease modifying treatments (DMT) in Spinal Muscular Atrophy (SMA), ongoing ventilatory requirements are common. Current guidelines suggest screening with oximetry with transcutaneous carbon dioxide (TcCO2). Aim: To determine the utility of pulse oximetry with TcCO2 as a screening tool for sleep disordered breathing (SDB) and need for Polysomnography(PSG)/Non-invasive ventilation (NIV) in children with SMA. Methods: A prospective cohort study was conducted in Queensland, Australia with diagnostic PSG completed in DMT naïve children. Transcutaneous carbon dioxide and pulse oximetry were recorded and extracted. Apnoea-hypopnoea indices (AHI) criteria, stratified by age, were applied to define normalcy and indication for non-invasive ventilation (NIV). Abnormal was defined as: ≤3 months of age [mo] AHI≥10 events/hour; > 3mo AHI ≥ 5events/hour. Receiver operating characteristic (ROC) curves and clinically meaningful cut-points were calculated for abnormal PSG and a variety of pulse oximetry/TcCO2 variables. Sensitivity, specificity, and predictive values are reported. Results: Total of45 children recruited (see table 1). The odds ratio of an abnormal PSG if the ODI4≥20 events/hour and a McGill score ≥ 2 was10.1 (95% CI 1.1-89.9; p=0.04). Conclusion: This is the first study to assess utility of pulse oximetry/TcCO2 to screen for need for NIV in children with SMA; particularly important where access to gold standard full diagnostic PSG is limited. TcCO2 adds limited information. Advantages of pulse oximetry: tolerated by children; versatile (e.g. ward/home); may avoid need for a diagnostic PSG(positive screen directed to NIV titration PSG) for some children. Findings need to be validated prospectively. Grant Support: Nil. This abstract is funded by: Nil.