Abstract: Objective To investigate the associated risk factors for Autism Spectrum Disorder (ASD) in children aged 2 to 6 years. Methods A multi-stage, stratified, cluster random sampling method was employed to select participants from seven communities and seven kindergartens. A final cohort of 1 895 children and their parents was recruited through simple random sampling from the combined lists. Data on the children and their parents, as well as early developmental and behavioral characteristics of the children, were collected via questionnaires. Descriptive epidemiological analysis was utilized to characterize the study population. Univariate and multivariate analyses were subsequently conducted to identify factors associated with the detection of ASD. Results Among the 1 810 children who completed the survey, 109 were preliminarily identified with ASD, of whom 54 received a definitive diagnosis. Multivariate logistic regression analysis revealed that several factors were significantly associated with an increased risk of ASD in children aged 2 to 6 years (all P<0.05). These risk factors included preterm birth (OR=1.670), maternal age at childbirth ≥30 years (OR=1.517), maternal anxiety and/or depression during pregnancy (OR=1.680), maternal history of occupational exposure to toxic substances (OR=2.784), frequent maternal use of electronic devices during pregnancy (OR=2.252), and average daily screen time of the child exceeding 2 hours (OR=1.982). Conclusion Preterm birth, advanced maternal age (≥30 years), maternal perinatal anxiety or depression, maternal occupational toxicant exposure, frequent maternal use of electronic devices during gestation, and excessive daily screen time (>2 hours) in early childhood are significant risk factors for ASD in children aged 2 to 6 years. These findings underscore the importance of developing targeted preventive and intervention strategies addressing these modifiable risk factors.

Key words: Autism spectrum disorder, Premature birth, Maternal age, Anxiety, Depression, Occupational exposure