Relation between early motor delay and later communication delay in infants at risk for autism

Background: Motor delays have been reported in retrospective studies of young infants who later develop Autism Spectrum Disorders (ASDs). Objective: In this study, we prospectively compared the gross motor development of a cohort at risk for ASDs; infant siblings of children with ASDs (AU sibs) to low risk typically developing (LR) infants. Methods: 24 AU sibs and 24 LR infants were observed at 3 and 6 months using a standardized motor measure, the Alberta Infant Motor Scale (AIMS). In addition, as part of a larger study, the AU sibs also received a follow-up assessment to determine motor and communication performance at 18 months using the Mullen Scales of Early Learning. Results: Significantly more AU sibs showed motor delays at 3 and 6 months than LR infants. The majority of the AU sibs showed both early motor delays and later communication delays. Limitations: Small sample size and limited follow-up. Conclusions: Early motor delays are more common in AU sibs than LR infants. Communication delays later emerged in 67-73% of the AU sibs who had presented with early motor delays. Overall, early motor delays may be predictive of future communication delays in children at risk for autism.