Duration of mechanical ventilation is more critical for brain growth than postnatal hydrocortisone in extremely preterm infants

Hydrocortisone is used in preterm infants. However, early disruption of growth velocities was observed in infants exposed to hydrocortisone. This retrospective study aimed to explore the postnatal brain growth of extremely preterm infants requiring hydrocortisone treatment as well as its association with perinatal factors. Extremely preterm infants exposed to hydrocortisone from 2011 to 2016 who survived up to 12 months were included. Each of them was matched with two infants not treated with hydrocortisone exhibiting similar gestational ages and nearly similar birth head circumferences. The outcome variables were brain tissue areas on MRIs performed at term-equivalent age and postnatal head circumference growth up to a corrected age of 12 months. Univariate and multiple regression analyses were performed. Infants treated with hydrocortisone (n=20) were matched with 40 infants not exposed to hydrocortisone. The infants exposed to hydrocortisone exhibited a lower birth weight (p=0.04) and a longer duration of mechanical ventilation (p<0.0001). Infants treated with hydrocortisone exhibited a smaller basal ganglia/thalamus area (p=0.04) at term-equivalent age and a smaller head circumference at a corrected age of 12 months (p=0.003). However, the basal ganglia/thalamus area and the postnatal brain growth were independently associated with the duration of mechanical ventilation and not with hydrocortisone. Interestingly, a significant interaction between hydrocortisone and sex was observed (p=0.04). Conclusion: This study supports previous data that indicated no obvious impact of hydrocortisone on brain growth and highlights the relationship between the severity of the neonatal course and postnatal brain growth in extremely preterm infants.

Automated summary

This study investigated the postnatal brain growth of extremely preterm infants requiring hydrocortisone treatment. The infants exposed to hydrocortisone showed smaller brain tissue areas at term-equivalent age and smaller head circumference at 12 months, but these effects were not directly associated with hydrocortisone treatment. Instead, brain growth was related to the duration of mechanical ventilation.