Objective Infants born extremely preterm (EP, <28 weeks’ gestation) exhibit poorer growth and neurodevelopmental impairment in early childhood compared with their term-born peers. Whether poor growth persists and whether associations of growth with neurodevelopmental functioning have changed in the decades since the introduction of surfactant are not well described. This study aims to (1) compare growth from birth to 2 years then 8 years in children born EP between three different eras, and (2) investigate the associations of growth from birth to 2 years then 8 years with cognitive, academic, executive and motor function at 8 years, and if associations have changed over time.

Design Prospective observational cohort studies in the State of Victoria, Australia in three discrete eras: 1991–1992, 1997 and 2005. EP children had weight and head circumference measured at birth, and weight, head circumference and height at 2 and 8 years. Cognitive ability, academic performance, executive function and motor skills were assessed at 8 years, corrected for prematurity.

Results 499/546 (91%) of surviving EP children were fully assessed at 8 years. Growth in children born EP did not differ substantially between eras and associations between growth and neurodevelopment did not change over time. Overall, better weight and head growth from birth to 2 years were associated with improved neurodevelopment at 8 years.

Conclusions Growth of children born EP has not improved in more recent eras. Better early head and weight growth are associated with improved neurodevelopment in mid-childhood.