Survival and neurodevelopmental outcomes in extremely preterm infants 22-24 weeks of gestation born in Western Australia

Aim: The management of births at borderline viability continues to present dilemmas for health professionals and parents. The aim of the study was to review local outcomes of infants born between 22 and 24 weeks of gestation between 2004 and 2010 in Western Australia (WA) to aid perinatal counselling.

Methods: Survival data for the study were sourced retrospectively from the Neonatal Clinical Care Unit and Department of Health records of births in WA. Neurodevelopmental follow-up outcomes were assessed using the most recent standardised assessment (Griffiths, Bayley-III and Wechsler Preschool and Primary Scale of Intelligence, 3rd Ed) and medical examination of infants/children 12 months to 8 years from follow-up clinic appointments.

Results: At these gestations, 159 survivors represented 72% of neonatal intensive care unit admissions, 53% of WA live births and 26% of WA live and still births; 5% of live births survived at 22 weeks, 46% at 23 weeks and 77% at 24 weeks. Of the 14 outborn/retrieved infants, 4 survived (29%). At a median age of 59 months, disabilities were severe in 13% of children (22-23w = 19%; 24w = 11%). The median test quotient was 90. Moderate and severe cognitive disability was found in 16%, cerebral palsy was found in 7% (n = 11), and 55% of children were free from impairment as defined in this study.

Conclusion: At these gestations, survival figures varied markedly with the chosen population denominator. Regional data are essential for valid population comparison. While many developmental difficulties occurred in these children, 78% were free from moderate or severe impairment at ages 3-5 years.