Effect of inborn vs. outborn delivery on neurodevelopmental outcomes in infants with hypoxic-ischemic encephalopathy: secondary analyses of the NICHD whole-body cooling trial.
BACKGROUND
The effect of birth location on hypothermia-related outcomes has not been rigorously examined in the literature. In this study, we determined whether birth location had an impact on the benefits of whole-body cooling to 33.5 °C for 72 h in term infants (n = 208) with hypoxic-ischemic encephalopathy (HIE) who participated in the Neonatal Research Network (NRN) randomized controlled trial.


METHODS
Heterogeneity by birth location was examined with respect to cooling treatment for the 18-mo primary outcomes (death, moderate disability, severe disability) and secondary outcomes (death, components of disability), and in-hospital organ dysfunction. Logistic regression models were used to generate adjusted odds ratios.


RESULTS
Infants born at a location other than an NRN center (outborn) (n = 93) experienced significant delays in initiation of therapy (mean (SD): 5.5 (1.1) vs. 4.4 (1.2) h), lower baseline temperatures (36.6 (1.2) vs. 37.1 (0.9) °C), and more severe HIE (43 vs. 29%) than infants born in an NRN center (inborn) (n = 115). Maternal education <12 y (50 vs. 14%) and African-American ethnicity (43 vs. 25%) were more common in the inborn group. When adjusted for NRN center and HIE severity, there were no significant differences in 18-mo outcomes or in-hospital organ dysfunction between inborn and outborn infants.


CONCLUSIONS
Although limited by sample size and some differences in baseline characteristics, the study showed that birth location does not appear to modify the treatment effect of hypothermia after HIE.
Department of Pediatrics, Wayne State University, Detroit, Michigan, USA. gnatara@med.wayne.edu
Girija
G
Natarajan
Athina
A
Pappas
Seetha
S
Shankaran
Abbot R
AR
Laptook
Michele
M
Walsh
Scott A
SA
McDonald
Richard A
RA
Ehrenkranz
Jon E
JE
Tyson
Ronald N
RN
Goldberg
Rebecca
R
Bara
Rosemary D
RD
Higgins
Abhik
A
Das
Breda
B
Munoz
D000328:Adult; D001831:Body Temperature; D016009:Chi-Square Distribution; D002657:Child Development; D002658:Developmental Disabilities / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D004185:Disability Evaluation; D005260:Female; D006297:Health Services Accessibility; D006700:Home Childbirth; D006761:Hospitals; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects / Q000401:mortality; D020925:Hypoxia-Ischemia, Brain / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D009420:Nervous System / Q000503:physiopathology*; D009483:Neuropsychological Tests; D016017:Odds Ratio; D010360:Patient Transfer; D012111:Residence Characteristics; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D061665:Time-to-Treatment; D016896:Treatment Outcome; D014481:United States; D055815:Young Adult