2. Procedures: Consented eligible patients will be randomly assigned to receive hydrocortisone in a tapering schedule over 7 days or placebo (comparison group). Study drug will be given every 12 hours IV with only study pharmacist aware of assignment. The patient's anatomic brain MRI (routinely done on all ELBW infants at 38 weeks post-menstrual age) will be further processed by the masked study investigators to derive total and regional brain volumes. Administration of indomethacin or dexamethasone to enrolled infants will be closely monitored and regulated throughout the trial period. Indomethacin use during study period is contraindicated. Dexamethasone (or other steroid) use will be restricted to ELBW infants on high ventilator settings (RIS > 10) after 28 days of life. All other procedures will be per routine care. Blinded developmental follow-up at two years, already currently performed for all ELBW infants at MHCH, will be analyzed and reported for all study infants.