Prevalence of Autism Spectrum Disorder and Associated Risk Factors among Children and Adolescents in Asia: A Systematic Review and Meta-Analysis

s Background : Autism Spectrum Disorder (ASD) is a diverse neurodevelopmental disorder that has been gaining popularity across the world. Despite Asia having a high percentage of children in the world, there is low reliable data on the prevalence of ASD due to variability in methods, differences in diagnostic criteria and access to diagnostic services. The aim of this systematic review and meta-analysis was to estimate the combined prevalence of ASD between children and adolescents in Asia as well as to pool evidence on risk factors associated with it. Methods : A systematic search of PubMed/MEDLINE, Scopus, Web of Science, Embase, PsycINFO, and the Cochrane Library was conducted to find population-based observational studies that reported ASD prevalence and/or risk factors in persons aged 0-19 years in Asian nations. The review was based on the PRISMA guidelines. Joanna Briggs Institute tools were used to determine the quality of the study. Random-effects meta-analysis was used to estimate prevalence (and 95% confidence intervals (CIs)) and subgroup analyses were undertaken to investigate the sources of heterogeneity. Results : A total of 28 studies published between 2005 and 2025, including 5,996,271 participants, met the inclusion criteria. Reported prevalence ranged from 0.016% to 15.56%. Using a random-effects model, the pooled prevalence of ASD was 1.37% (95% CI: 0.36–3.01) with a high degree of heterogeneity (I² = 99.99%). Prevalence differed significantly by diagnostic method: DSM-IV–based studies reported 2.12% (95% CI: 0.76–4.13), M-CHAT screening 0.29% (95% CI: 0.19–0.41), and ICD-10–based studies 1.50% (95% CI: 0.45–9.47). Male dominance was also regular, with male to female ratios of 2:1 to 4:1 and prevalence was typically higher in urban populations. Multiple investigations found a correlation between ASD prevalence and sociodemographic, prenatal, and perinatal factors, but could not determine causation because of cross-sectional study designs. New methods being considered that might help improve early ASD detection in resource-constrained environments include explainable feature-based algorithms and web-based applications. Conclusions : The prevalence of ASD in children and adolescents in Asia is significant and highly dissimilar; it is greatly affected by the criteria of the diagnosis process, the type of study design, and the healthcare infrastructure. The results point to the ongoing under-option of under-resourced environments and to the immediate necessity of universally standardized, culturally transformed screening and diagnostic models, enhanced surveillance, and fair accessibility to early detection within Asian nations.