Prophylactic low-dose hydrocortisone in neonates born extremely preterm: current knowledge and future challenges.

Prophylactic administration of low-dose hydrocortisone, at replacement dosage, targets inability of extremely low gestational age neonates (ELGANs) to respond to postnatal stress due to adrenal glands immaturity and is intended to prevent serious complications such as death and bronchopulmonary dysplasia (BPD). Increasing evidence from systematic reviews shows that prophylactic hydrocortisone reduces pre-discharge mortality, improves survival without BPD, favors patent ductus arteriosus (PDA) closure, and may have beneficial effects on cardiovascular stability and urine output. In contrast, an increased risk of spontaneous intestinal perforation when prophylactic hydrocortisone is combined with indomethacin and late-onset sepsis, particularly in infants of 24-25 weeks of gestation, have been reported as major adverse events. No significant negative impact on long-term neurodevelopmental outcomes following prophylactic hydrocortisone exposure was observed. Recent real-world data, despite their intrinsic methodological limitations, generally confirm the benefits observed in clinical trials, even with additional potential benefits and without increased adverse events. Ongoing challenges and questions discussed in this invited review relate to the best population to treat, optimal timing and duration of treatment, and potential barriers to implementation due to evolving knowledge and guidelines. IMPACT STATEMENT: Prophylactic low-dose hydrocortisone improves survival without BPD in infants born extremely preterm. Recent real-world data generally confirm the benefits observed in clinical trials, even with additional potential benefits and without increased adverse events. Unanswered questions remain about optimal timing and duration of treatment, and potential barriers to implementation due to evolving knowledge and guidelines.