Two-year neurodevelopmental outcomes of extremely preterm infants treated with early hydrocortisone: treatment effect according to gestational age at birth

Objective To determine whether early hydrocortisone treatment in extremely preterm infants affects neurodevelopmental outcomes at 2 years of age according to gestational age at birth. Patients and methods This is an exploratory analysis of neurodevelopmental outcomes by gestational age strata from the PREMILOC trial, in which patients were randomly assigned to receive either placebo or low-dose hydrocortisone and randomisation was stratified by gestational age groups (24-25 and 26-27 weeks of gestation). Neurodevelopmental impairment (NDI) was assessed using a standardised neurological examination and the revised Brunet-Lezine scale at 22 months of corrected age. Results A total of 379 of 406 survivors were evaluated, 96/98 in the gestational age group of 24-25 weeks and 283/308 in the gestational age group of 26-27 weeks. Among surviving infants born at 24-25 weeks, significant improvement in global neurological assessment was observed in the hydrocortisone group compared with the placebo group (P=0.02) with a risk of moderate-to-severe NDI of 2% and 18%, respectively (risk difference 16 (95% CI -28% to -5%)). In contrast, no statistically significant difference between treatment groups was observed in infants born at 26-27 weeks (P= 0.95) with a similar risk of moderate-to-severe NDI of 9% in both groups. The incidence of cerebral palsy or other major neurological impairments were found similar between treatment groups in each gestational group. Conclusions In an exploratory analysis of neurodevelopmental outcomes from the PREMILOC trial, early low-dose hydrocortisone was associated with a statistically significant improvement in neurodevelopmental outcomes in infants born at 24 and 25 weeks of gestation.