The changing relationship between bronchopulmonary dysplasia and cognition in very preterm infants

Aim: To characterise the relationship between bronchopulmonary dysplasia (BPD) severity and cognition in the post-surfactant era. Methods: This was a single-centre retrospective analysis of a cohort of infants born 2009-2012. Inclusion criteria were as follows: admission within 48 hours of birth, gestational age 22-0/7-31-6/7 weeks, birthweight 400-1500 g and Bayley Scales of Infant and Toddler Development-III testing at 18-26 months corrected age. Infants (n = 151) were classified by BPD severity with the NIH Workshop definition. Generalised linear modelling and multivariate logistic regression were performed. Results: Bayley cognitive score was not associated with BPD severity in univariate (p = 0.053) or multivariate (p = 0.503) analysis. About 27% of infants with no/mild BPD, 33% of infants with moderate BPD and 40% of infants with severe BPD had a cognitive score < 85. There was no difference in the odds of cognitive score < 85 based on BPD severity in univariate (p = 0.485) or multivariate analysis (p = 0.225). All infants with cognitive score < 70 had severe BPD, although the association between cognitive score < 70 and BPD severity was not significant. Conclusion: We found no independent effect of BPD severity level on cognition. The likelihood of a cognitive score < 85 was not associated with BPD severity.