Interaction of hydrocortisone and illness severity on head growth in cohort of ELBW infants

Extremely low birth weight (ELBW) infants comprise a fragile population at risk for neurodevelopmental disabilities (NDD). Systemic steroids were previously associated with NDD, but more recent studies suggest hydrocortisone (HCT) may improve survival without increasing NDD. However, the effects of HCT on head growth adjusted for illness severity during NICU hospitalization are unknown. Thus, we hypothesize that HCT will protect head growth, accounting for illness severity using a modified neonatal Sequential Organ Failure Assessment (M-nSOFA) score. We conducted a retrospective study that included infants born at 23–29 weeks gestational age (GA) and < 1000 g. Our study included 73 infants, 41% of whom received HCT. We found negative correlations between growth parameters and age, similar between HCT and control patients. HCT-exposed infants had lower GA but similar normalized birth weights; HCT-exposed infants also had higher illness severity and longer lengths of hospital stay. We found an interaction between HCT exposure and illness severity on head growth, such that infants exposed to HCT had better head growth compared to those not exposed to HCT when adjusted for illness severity. These findings emphasize the importance of considering patient illness severity and suggest that HCT use may offer additional benefits not previously considered.