Introduction
Bronchopulmonary dysplasia (BPD) is a chronic inflammatory lung disease that occurs as a common complication of preterm birth. Preterm infants with BPD are at higher risk of mortality or neurodevelopmental impairment. It is known that postnatal corticosteroid (PNC) therapy effectively reduces the incidence of BPD, but PNC use remains controversial due to concerns of adverse effects on the developing brain. We hypothesize that low-dose PNC therapy for very preterm (VPT, ≤ 32 weeks gestational age [GA]) infants at risk for BPD is associated with improved brain injury and maturation outcomes, when compared to at-risk VPT infants who did not receive therapy.

Methods
We enrolled 392 VPT infants as part of a large prospective cohort study. Structural MRI was acquired at term-equivalent age. We used the developing Human Connectome Project pipeline to derive brain volumes and cortical morphometrics. We calculated a propensity score for each subject, representing the subject’s probability of receiving PNC based on their clinical and demographic factors. This score was used in weighted linear regression to determine the effect of PNC on measures of brain development.

Results
Of 392 VPT infants, 41 received PNC for BPD: 21 males; mean (SD) GA 25.5 (1.6) weeks; postmenstrual age at MRI 43.7 (1.2) weeks; 33 had severe BPD. In multiple linear regression, PNC was positively associated with volume of the corpus callosum and bilateral amygdala, hippocampus, and deep gray matter; surface area of the frontal lobe, insula, and left temporal/parietal lobes; sulcal depth of the occipital, parietal, and temporal lobes, and curvature of the left insula and occipital/left temporal lobes. PNC was negatively associated with sulcal depth of the frontal lobe and curvature of the left frontal lobe.

Conclusions
Low-dose PNC therapy for BPD does not have a widespread, adverse effect on brain development and may be neuroprotective in specific brain regions of VPT infants at term-equivalent age.

Acknowledgements
This study was supported in part by NIH grant T35DK060444.

Key Words
Preterm birth, Bronchopulmonary Dysplasia, Neurodevelopment, Structural MRI, Neonatology

Contact Information
Rahul Chandwani
University of Cincinnati College of Medicine, MS2
chandwrl@mail.uc.edu
503-438-9420