Grant: Travel Awards - Institute Community Support

Infants born before 32 weeks of completed gestation (i.e., born very preterm (VPT)) enter the extra-uterine environment with lungs that aren't fully developed, putting them at high risk for respiratory morbidities (RM) which include severe cardiorespiratory events (CRE) defined as apnea (i.e., temporary cessation of breathing), bradycardia (i.e., slow heart rate), and/or desaturation (i.e., low levels of oxygen) requiring intervention and a prolonged need for respiratory support (RS) and/or oxygen therapy. Previous research has shown that the CA1 region of the hippocampus might be sensitive to changes in oxygen levels, which can occur during these RM. Whether RM-specific CA1 alterations can be detected in infants born VPT remains to be determined. This study aims to examine the relationships between RM and bilateral CA1 volumes at term-equivalent age (TEA) in infants born VPT using magnetic resonance imaging (MRI). Secondary analyses will also explore the associations between RM and remaining hippocampal subregions. To do so, 36 VPT participants completed a brain MRI at TEA. The number of severe CRE, RS duration, and O2 therapy duration from birth until 40 weeks GA were collected from their medical records. Statistical analyses were performed to determine the effects of each RM on bilateral CA1 volumes, as well as the remaining subregions volumes. We found that an higher number of CRE was associated with smaller bilateral CA1 volumes at TEA. A higher number of CRE was also associated with smaller right CA2/CA3 (p=0.02) and right total hippocampus volume (p=0.022). RS duration and O2 therapy duration were not associated with total or regional hippocampal volumes. These results could lead to discussions with clinicians on how to better care for these babies, including more careful monitoring and possible adjustments in treatment. We plan to expand this study by including a larger group of VPT infants and considering more factors to better understand this association.