Relationships of Severity of Bronchopulmonary Dysplasia with Adverse Neurodevelopmental Outcomes and Poor respiratory Function at 7-8 Years of Age

Objective To clarify the relationships of three definitions of severity of bronchopulmonary dysplasia (BPD) with adverse neurodevelopmental and respiratory outcomes at early school-age. Study design Participants comprised 218 consecutive survivors to 7-8 years of age born either <28 weeks’ gestation or weighing <1000 g in Victoria, Australia, in 2005. BPD was classified as none, Grade 1 (mild), Grade 2 (moderate), or Grade 3 (severe), using two commonly accepted definitions: 1) Jobe2001, and 2) Higgins2018, and our own 3) VICS2005, adapted from Jensen2019. Outcomes included major neurodevelopmental disability, low intelligence quotient and academic achievement, poor motor function, and poor respiratory function as assessed by spirometry. Outcomes for children with each grade of BPD were compared with children with no BPD. Results Of the 218 survivors, 132 (61%) had BPD on Jobe2001 criteria, and 113 (52%) had BPD on both Higgins2018 and VICS2005 criteria. Grade 1 on any criteria was not associated with any adverse neurodevelopmental outcomes. Grade 1 on both Higgins2018 and VICS2005 was associated with reduced spirometry. Grade 2 on both Higgins2018 and VICS2005, and Grade 3 on all criteria were associated with increased risk for both adverse neurodevelopmental and respiratory outcomes. Conclusions Compared with no BPD, receiving additional oxygen up to 29% but no positive pressure support at 36 weeks’ postmenstrual age increased the risk of abnormal respiratory function but not adverse neurodevelopment. Receiving ≥30% oxygen or any positive pressure support at 36 weeks increased the risk of both adverse outcomes.