Outborns or Inborns: Where Are the Differences? A Comparison Study of Very Preterm Neonatal Intensive Care Unit Infants Cared for in Australia and New Zealand and in Canada

Abstract

Background: Very preterm infants born outside tertiary centers are at higher risks of adverse outcomes than inborn infants. Regionalization of perinatal care has been introduced worldwide to improve outcomes. Objective: To compare the risk-adjusted outcomes of both inborn and outborn infants cared for in tertiary neonatal intensive care units in Australia and New Zealand and in Canada. Methods: Deidentified data of infants <32 weeks' gestational age from the 29 Australian and New Zealand Neonatal Network units (ANZNN; n = 9,893) and 26 Canadian Neonatal Network units (CNN; n = 7,133) between 2005 and 2007 were analyzed for predischarge adverse outcomes. Results: ANZNN had lower rates of outborns compared to CNN (13 vs. 19%), particularly of late admissions (>2 days of age; 5.8 vs. 22.2% of outborns) who had high morbidity rates. After adjusting for confounding variables including gestation, ANZNN inborn infants had lower odds of chronic lung disease [CLD; 17.0 vs. 23.3%; adjusted odds ratio (AOR) = 0.70, 95% CI: 0.64-0.77], severe neurological injuries on ultrasound (SNI; 4.1 vs. 6.7%; AOR = 0.62, 95% CI: 0.53-0.73), severe retinopathy (5.6 vs. 7%; AOR = 0.71, 95% CI: 0.59-0.84) and necrotizing enterocolitis (3.5 vs. 5.4%; AOR = 0.67, 95% CI: 0.56-0.79), but no difference in mortality odds. After excluding the late outborn admissions, ANZNN outborns had lower odds of SNI (AOR = 0.43, 95% CI: 0.32-0.58) and CLD (AOR = 0.63, 95% CI: 0.49-0.81) than CNN. Conclusions: ANZNN inborn and early admitted outborn infants had lower odds of neonatal morbidities than their CNN counterparts. However, compared to ANZNN, the higher CNN rates of outborns and their late admissions are likely related to the differences in regionalization and referral practices, and may explain differences in outcomes.

Restricted Ventilation Associated with Reduced Neurodevelopmental Impairment in Preterm Infants

“…To maximize comparability of both epochs, we only included infants born ≥25 weeks' gestation in this analysis. Furthermore, we identified all possible confounders based on a known association with one or more of the main outcomes mortality, BPD, and NDI (GA, small for gestational age defined as weight <10th percentile according to the Dutch reference curves, chorioamnionitis, singleton, and outborn), or differences between both epochs in the univariate analysis with p < 0.2 (Apgar score) [15,16,17]. Next, we performed a multiple logistic regression analysis correcting for these confounders present at birth.…”

Necrotizing enterocolitis: new insights into pathogenesis and mechanisms

“…In the USA alone, the rate of prematurity is about 10% of all births, with rates as high as 13.23% in black individuals of non-Hispanic origin 9 . Large, population-based and hospital-based multicentre studies coordinated by neonatal research networks in Europe, North America, Australia and New Zealand have determined the incidence of NEC to be up to 13% among infants born ≤33 weeks of gestation or whose birth weight is ≤2,500 g 1,10–18 . Interestingly, the incidence of NEC among extremely preterm neonates in US academic centres has seen either a stabilization or even a decline to about 9% in the past 5 years analysed 1 , a trend that might reflect increased vigilance and the implementation of standardized feeding strategies 19 .…”

Selection Bias and Outcomes for Preterm Neonates

“…Also, outborn status has previously been found to be important in the Australian context. 18 The data sets were also unable to quantify other factors important in counseling that may influence the decision to admit to NICU, including the clinician and family's beliefs and values, because this may lead to a rational decision to choose palliative care. 1,19 Provision of active perinatal management both reflects and determines survival and neurodevelopmental outcomes.…”