Beyond the borderline: Outcomes for inborn infants born at ≤500 grams

Aim To report survival, morbidity and neurodevelopmental outcome in a cohort of extremely low birthweight infants. Methods Retrospective cohort study of all inborn infants born alive with birthweights ≤500 g ≥22 weeks gestation at Women's and Children's Hospital, Adelaide, Australia, over a 6-year period (2005-2010). Outcome data including standardised medical and psychological assessments at 12 and 36 months corrected age were collated from follow-up. Results A total of 36 eligible infants were born over the study period (mean gestational age (GA) 24.4 (range 22.0-30.0) weeks; birthweight 443 (330-500) grams). Twenty-six of the 36 (72%) infants were small for gestational age (SGA).Ten of the 36 infants received compassionate care and died in the delivery or operating room. Twenty-six of the 36 infants were admitted to the neonatal intensive care unit (NICU), of whom 12 (46%) died during their admission. At age 12 months corrected, 2/14 (14%) of survivors had none/minimal, 4/14 (29%) had mild and 8/14 (57%) had moderate/severe neurodevelopmental disability. Overall, the survival rate was 39%, and survival without neurodevelopmental disability was 6%. Only 1/10 appropriate-for-gestational-age (AGA) infants survived to discharge (and had severe disability), whereas 13/26 (50%) of all SGA infants in the study survived to discharge. Of all infants admitted to the NICU, 11/26 (42%) survived without severe neurodevelopmental disability at latest follow-up. Conclusions There was a high risk of death or impairment in this cohort of infants. Survival was rare for AGA infants weighing ≤500 g at birth. Our study provides an evidence base to assist counselling and decision-making.