Short-term outcomes of asphyxiated neonates depending on outborn versus inborn status
Authors: Bruns Nora , Feddahi Nadia , Hojeij Rayan , Rossi Rainer , Dohna-Schwake Christian , Stein Anja , Kobus Susann , Stang Andreas , Kowall Bernd , Felderhoff-Müser Ursula 
Published: March 2024

Importance

In 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.

Objective

To 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).

Design

Nationwide retrospective cohort study from a comprehensive hospital dataset using codes of the International Classification of Diseases, 10thmodification (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.

Setting

All admissions to German hospitals 2016 – 2021.

Participants

Full term neonates with birth asphyxia (ICD-10 code: P21) admitted to a pediatric department on their first day of life.

Exposures

Transfer to a pediatric department within 24 hours of admission to an external hospital (=outborn).

Main outcomes

In-hospital death; secondary outcomes: seizures and pediatric complex chronic conditions category (PCCC) ≥ 2.

Results

Of 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 relevance

This 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 points

Question

How does outcome in neonates with birth asphyxia differ depending on postnatal transfer status to a pediatric department?

Findings

In 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.

Meaning

To 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.