RT Journal Article SR Electronic T1 Associations between physical activity and development in preschool-aged children born <30 weeks’ gestation: a cohort study JF Archives of Disease in Childhood - Fetal and Neonatal Edition JO Arch Dis Child Fetal Neonatal Ed FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 602 OP 608 DO 10.1136/archdischild-2023-326045 VO 109 IS 6 A1 FitzGerald, Tara L A1 Cameron, Kate L A1 Albesher, Reem A A1 Mentiplay, Benjamin F A1 Mainzer, Rheanna M A1 Burnett, Alice C A1 Treyvaud, Karli A1 Clark, Ross A A1 Anderson, Peter J A1 Cheong, Jeanie LY A1 Doyle, Lex W A1 Spittle, Alicia J YR 2024 UL http://fn.bmj.com/content/109/6/602.abstract AB Objective To investigate the effect of physical activity (PA) on development (motor, cognitive, social-emotional) in children 4–5 years old born <30 weeks’ gestation, and to describe subgroups of children at risk of low PA in this cohort.Design Longitudinal cohort study.Patients 123 children born <30 weeks were recruited at birth and assessed between 4 and 5 years’ corrected age.Main outcome measures Development was assessed using the Movement Assessment Battery for Children, Second Edition (MABC-2), Little Developmental Coordination Disorder Questionnaire (L-DCDQ), Wechsler Preschool and Primary Scale of Intelligence (Fourth Edition; WPPSI-IV), and Strengths and Difficulties Questionnaire (SDQ). To measure PA, children wore an accelerometer and parents completed a diary for 7 days. Effects of PA on developmental outcomes, and associations between perinatal risk factors and PA, were estimated using linear regression.Results More accelerometer-measured PA was associated with better MABC-2 aiming and catching scores (average standard score increase per hour increase in PA: 0.54, 95% CI 0.11, 0.96; p=0.013), and lower WPPSI-IV processing speed index scores (average composite score decrease per hour increase in PA: −2.36, 95% CI −4.19 to –0.53; p=0.012). Higher accelerometer-measured PA was associated with better SDQ prosocial scores. Major brain injury in the neonatal period was associated with less moderate-vigorous and less unstructured PA at 4–5 years.Conclusions Higher levels of PA are associated with aspects of motor, cognitive and social-emotional skill development in children 4–5 years old born <30 weeks. Those with major brain injury in the neonatal period may be more vulnerable to low PA at preschool age.Data are available upon reasonable request. Data available upon reasonable request to the corresponding author.