Developmental Profile of Low Risk Children with Autism Spectrum Disorder during the First Two Year of Life
Early recognition of autism spectrum disorder (ASD) enables early interventions which had been shown to improve clinical outcome. Defining the patterns of developmental trajectory of children with ASD across different developmental domains can contribute to better understanding of the neurobiology of ASD and to improved screening tools and earlier referral for diagnosis. Data regarding the acquisition of developmental milestones in children with ASD is scares and mostly derived from retrospective recall of parents. In Israel a nationwide computerized well care baby system contains data on children's achievement of developmental milestones gathered prospectively by a trained nurse during routine checkups in the first years of life. This database enables a prospective outline of the developmental trajectory across several developmental domains using uniform scales in different population groups.
Objectives: To outline the acquisition of milestones in different developmental domains in low risk children later diagnosed with ASD compared to typically developing (TD) children and to identify early signs observed in routine well care baby checkups that could indicate referral for further evaluation.
We compared early developmental data of 355 children with ASD to matched 416 typically developing children using the well care baby database. Data was prospectively collected at 6 weeks and 3, 6, 9, 12, 18 and 24 months during regular checkup visits. In each visit 5 to 6 items representing different developmental domains (gross motor, fine motor, social, receptive and expressive language) were evaluated and recorded. Children with major developmental disabilities (such as cerebral palsy, genetic syndromes) and risk factors (such as prematurity) were excluded.
Results: Difference in acquisition of milestones between ASD a TD groups emerged at 9 months. 31% of children in ASD group failed the receptive language item compared to 12% in the TD group (p=0.0001), 40% in ASD group failed the gross motor item compared to 22% in TD group (p=0.002), 19% of ASD group failed the fine motor item compared to 8% in TD group (p=0.003), 16% of ASD group failed the social item compared to 9% of TD group (p=0.05). Difference in the expressive pre-verbal item was non-significant. At 12, 18, 24 months, differences between groups were highly significant in all developmental domains.
Deviation from typical developmental trajectory is observed early, at nine month of age, in low risk children later diagnosed with ASD. This difference is especially prominent in receptive language and gross motor domains. Children representing these developmental delays should be closely monitored for communication deficit, for early diagnosis and treatment.