Lung Ultrasound Score (LUS) as Early Predictor of Bronchopulmonary Dysplasia (BPD) in Preterm Newborns: A Prospective, Multicenter, Observational Study

Bronchopulmonary dysplasia (BPD) is one of the most frequent and severe complications of extreme prematurity and remains a major cause of neonatal morbidity despite significant advances in perinatal and neonatal care. BPD is associated with long-term respiratory, cardiovascular, and neurodevelopmental complications and continues to affect a substantial proportion of infants born at very low gestational ages. Current diagnostic definitions of BPD rely on the need for respiratory support at 36 weeks postmenstrual age. Consequently, diagnosis is established after the period during which preventive and disease-modifying interventions are likely to be most effective. Evidence suggests that irreversible structural changes of the developing lung may occur within the first weeks of life, making early identification of infants at high risk of BPD a clinical priority. Lung ultrasound (LUS) has emerged as a safe, non-invasive, bedside imaging modality capable of assessing lung aeration and pulmonary abnormalities in preterm infants. The Lung Ultrasound Score (LUS) provides a quantitative evaluation of lung aeration loss and has shown promising results in predicting respiratory outcomes in neonatal populations. In addition, pleural line abnormalities, including thickening, irregularity, fragmentation, and subpleural consolidations, have been associated with the subsequent development of BPD. Although several studies have suggested that lung ultrasound findings obtained during the first two weeks of life may predict BPD, no standardized and universally accepted method for early risk stratification is currently available. Furthermore, the optimal ultrasound parameters and their predictive performance remain uncertain. The first 15 days of life represent a critical window for assessing the risk of BPD and for identifying infants who may benefit from preventive therapeutic strategies before irreversible lung injury develops. The aim of this study is to evaluate whether lung ultrasound findings obtained during the first two weeks of life, including Lung Ultrasound Score and pleural line characteristics, are associated with the subsequent development of BPD and may therefore serve as early prognostic markers. Because two clinical definitions of BPD are currently widely used in clinical practice and research, and no clear evidence has demonstrated the superiority of one definition over the other for diagnostic or prognostic purposes, both the Jobe and Bancalari definition and the Jensen definition will be applied in this study. The primary objective is to evaluate the diagnostic performance of the Lung Ultrasound Score measured at 7 and 14 days of life for the prediction of BPD and moderate-to-severe BPD in preterm infants.