Prevalence of autism spectrum disorder diagnosed according to DSM-5 criteria and associated factors in preschoolers in southern Vietnam.

Introduction: Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder that has become a significant concern in pediatric mental health due to its rising prevalence in recent years. Despite this increase, the prevalence of ASD and its associated risk factors remain poorly understood. This study aims to elucidate the prevalence of ASD and its associated risk factors among preschool children in southern Vietnam.

Methods: This prospective study was conducted from June 2021 to December 2022 and included 9,397 children (4,813 boys and 4,584 girls) aged 24 to 72 months, attending 41 kindergartens in southern Vietnam. Diagnoses of ASD were made by qualified pediatric psychiatrists using DSM-5 criteria. Data on ASD-related variables were collected through a structured questionnaire administered by trained preschool teachers. Univariate logistic regression analysis was employed to identify associations between independent variables and the prevalence of ASD, followed by multivariate logistic regression models to control for potential confounders.

Results: The overall prevalence of ASD among children aged 24 to 72 months attending preschool in southern Vietnam was found to be 1.2% (1 in 84 children). The prevalence rates in central, subcentral, and suburban areas were 2.00%, 0.6%, and 1%, respectively. Significant risk factors for ASD identified through multivariate regression analysis included age (24 to 30 months) with an odds ratio (OR) of 5.35 (95% CI: 2.84-10.10), male gender (OR=2.55, 95% CI: 1.68-3.86), maternal exposure to pesticides (OR=4.62, 95% CI: 1.84-11.61), maternal stress or psychological trauma during pregnancy (OR=2.3, 95% CI: 1.1-5.4).

Conclusion: ASD represents a significant pediatric psychiatric issue in southern Vietnam, with a higher incidence than previously reported. Some of the identified risk factors are potentially preventable, suggesting that targeted interventions could reduce the incidence of ASD.