Two-year neurodevelopmental outcome in extremely preterm-born children: The Austrian Preterm Outcome Study Group.

Aim: The current study determined the neurodevelopmental outcome of extremely preterm infants at 2 years of age.

Methods: All live-born infants 23-27 weeks of gestation born between 2011 and 2020 in Austria were included in a prospective registry. Neurodevelopmental outcome at 2 years of corrected age was assessed using Bayley Scales of Infant Development for both motor and cognitive scores, along with a neurological examination and an assessment of neurosensory function.

Results: 2378 out of 2905 (81.9%) live-born infants survived to 2 years of corrected age. Follow-up data were available for 1488 children (62.6%). Overall, 43.0% had no, 35.0% mild and 22.0% moderate-to-severe impairment. The percentage of children with moderate-to-severe neurodevelopmental impairment decreased with increasing gestational age and was 31.4%, 30.5%, 23.3%, 19.0% and 16.5% at 23, 24, 25, 26 and 27 weeks gestational age (p < 0.001). Results did not change over the 10-year period. In multivariate analysis, neonatal complications as well as male sex were significantly associated with an increased risk of neurodevelopmental impairment.

Conclusion: In this cohort study, a 22.0% rate of moderate-to-severe neurodevelopmental impairment was observed among children born extremely preterm. This national data is important for both counselling parents and guiding the allocation of health resources.