Effect of Early Hydrocortisone on Risk of Gastrointestinal Perforations in Extremely Preterm Infants

"Cohort members will be considered to be exposed to early hydrocortisone if either:~1. They receive early hydrocortisone started on postnatal day 1 or 2 and given for more than seven consecutive days OR~2. They receive early hydrocortisone started on postnatal day 1 or 2 and are being cared for in a PROHYDRO unit but die on or before postnatal day 8.~PROHYDRO units are defined as units who, at the time the baby was born, had implemented a protocol for use of prophylactic hydrocortisone as part of routine care for babies born less than 28 weeks' gestation. A unit may change from being a non-PROHYDRO unit to a PROHYDRO unit if a new early hydrocortisone protocol is introduced during the study period (2016-2023)."