Associations between physical activity and development in preschool-aged children born <30 weeks' gestation: a cohort study

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.