Objectives To (1) compare the neurodevelopmental outcomes at 8 years of age of children born extremely preterm (EP) who underwent surgical procedures during the course of their initial hospital admission with those who did not and (2) compare the outcomes across eras, from 1991 to 2005.

Design Prospective observational cohort studies conducted over three different eras (1991-1992, 1997 and 2005). Surviving EP children, who required surgical intervention during the primary hospitalisation, were assessed for general intelligence (IQ) and neurosensory status at 8 years of age. Major neurosensory disability comprised any of moderate/severe cerebral palsy, IQ less than -2 SD relative to term controls, blindness or deafness.

Results Overall, 29% (161/546) of survivors had surgery during the newborn period, with similar rates in each era. Follow-up rates at 8 years were high (91%; 499/546), and 17% (86/499) of survivors assessed had a major neurosensory disability. Rates of major neurosensory disability were substantially higher in the surgical group (33%; 52/158) compared with those who did not have surgery (10%; 34/341) (OR 4.28, 95% CI 2.61 to 7.03). Rates of disability in the surgical group did not improve over time. After adjustment for relevant confounders, no specific surgical procedure was associated with increased risk of disability.

Implications and relevance Major neurosensory disability at 8 years was higher in children born EP who underwent surgery during their initial hospital admission compared with those who did not. The rates of major neurosensory disability in the surgical cohort are not improving over time.