Short-term outcomes of asphyxiated neonates depending on outborn versus inborn status

ImportanceIn neonates with birth asphyxia (BA) and hypoxic ischemic encephalopathy, therapeutic hypothermia (TH), initiated within six hours, is the only safe and established neuroprotective measure to prevent secondary brain injury. Infants born outside of TH centers have delayed access to cooling. ObjectiveTo compare in-hospital lethality, occurrence of seizures, and functional status at discharge in newborns with BA depending on postnatal transfer to another hospital within 24 hours of admission (outborn versus inborn). DesignNationwide retrospective cohort study from a comprehensive hospital dataset using codes of the International Classification of Diseases, 10th modification (ICD-10). Clinical and outcome information was retrieved from diagnostic and procedural codes. Hierarchical multilevel logistic regression modelling was performed to quantify the effect of being outborn on target outcomes. SettingAll admissions to German hospitals 2016 - 2021. ParticipantsFull term neonates with birth asphyxia (ICD-10 code: P21) admitted to a pediatric department on their first day of life. ExposuresTransfer to a pediatric department within 24 hours of admission to an external hospital (=outborn). Main outcomesIn-hospital death; secondary outcomes: seizures and pediatric complex chronic conditions category (PCCC) [≥] 2. ResultsOf 11,703,800 pediatric cases, 25,914 fulfilled the inclusion criteria. Outborns had higher proportions of organ dysfunction, TH, organ replacement therapies, and neurological sequelae in spite of slightly lower proportions of maternal risk factors. The adjusted odds ratios (OR) for death, seizures, and PCCC [≥] 2 were 4.08 ((95 % confidence interval 3.41 - 4.89), 2.99 (2.65 - 3.38), and 1.76 (1.52 - 2.05), respectively, if infants were outborn compared to inborn. A subgroup analysis among infants receiving TH (n = 3,283) found less pronounced adjusted ORs for death (1.67 (1.29 - 2.17)) and seizures (1.26 (1.07 - 1.48)) and inversed effects for PCCC [≥] 2 (0.81 (0.64 - 1.02)). Conclusion and relevanceThis comprehensive nationwide study found increased odds for adverse outcomes in neonates with BA who were transferred to another facility within 24 hours of hospital admission. Obstetrical units should be linked to a pediatric department to minimize risks of postnatal emergency transfer. Collaboration and coordination between centers should be improved to balance geographical coverage of different level care facilities. Key pointsO_ST_ABSQuestionC_ST_ABSHow does outcome in neonates with birth asphyxia differ depending on postnatal transfer status to a pediatric department? FindingsIn this comprehensive nationwide cohort study from administrative data including 35,250 cases, outborns had increased odds for death, seizures, and impaired functioning in spite of similarly distributed maternal risk factors and lower prevalence of infant risk factors. MeaningTo prevent postnatal transfer and potential delays in optimal neonatal care, maternity hospitals should invariably be combined with a pediatric unit. Neonatal emergency trainings and telemedicine may help to attenuate the adverse effects of being born in a non-TH center and in settings without access to a pediatric unit.