Neurodevelopmental outcomes of extremely preterm infants in New South Wales and the Australian Capital Territory.

AIM: This study aimed to provide updated information on gestation-specific neurodevelopmental outcomes of extremely to very preterm infants 23-28 weeks' gestation admitted to neonatal intensive care units (NICUs).

METHODS: This was a population-based retrospective cohort study of infants born between 23+0 and 28+6 weeks' gestation and admitted to a network of NICUs between 2007 and 2012 in a well-defined geographic area of New South Wales (NSW) and the Australian Capital Territory (ACT). Primary outcome was moderate to severe neurodevelopmental impairment.

RESULTS: Of 2287 infants admitted to NICUs, 1914 (83.7%) survived to discharge, and 1514 (79.8% = 1514/1897) were followed up. Moderate to severe neurodevelopmental impairment was 11% overall, and the incidence decreased with increasing gestational age (GA): 25, 23, 15, 13, 9 and 7% at 23, 24, 25, 26, 27 and 28 weeks, respectively. Male gender, major intraventricular haemorrhage, late-onset sepsis, chronic lung disease and post-natal corticosteroid therapy were found to be independently associated with increased risk of moderate to severe impairment. Compared with an incidence of 16% in the 1998-2004 cohort, there was a significant reduction in moderate to severe neurodevelopmental impairment in the current cohort (unadjusted odds ratio: 0.65, 95% confidence interval: 0.52-0.80).

CONCLUSIONS: We report the latest neurodevelopmental outcomes of extremely to very preterm infants in NSW and the ACT. Neurodevelopmental outcome rates based on GA alone may not provide the true estimate as these outcomes can vary based on the presence or absence of other relevant perinatal factors.