Preregistration documents for A systematic review on the effects of multilingual exposure on language and developmental outcomes in children with Autism Spectrum Disorder in different geographic and linguistic contexts

In the neurodevelopmental condition of Autism Spectrum Disorder (ASD), language and cognitive abilities can differ widely, ranging from minimal verbal speech to fluent language and from intellectual disability to average or above-average cognition. Given these diverse profiles, children with ASD growing up in multilingual environments may face unique challenges and opportunities in language development, social interaction, and adaptive functioning.  Early interventions have consistently been shown to improve developmental outcomes in children with ASD, particularly in areas of communication and social skills (Dawson et al., 2010; Rogers and Vismara, 2008). Simultaneously, an increasing number of children diagnosed with ASD are growing up in multilingual environments, especially in Asian contexts where bilingualism or multilingualism are common (Qiu et al., 2019). Among typically developing children, multilingual exposure has been associated with cognitive advantages such as enhanced executive functioning and metalinguistic awareness (Bialystok, 2015). However, the effects of multilingual exposure on children with ASD remain less clear.  Existing studies on language interventions for children with ASD have largely focused on Western contexts (Beauchamp et al., 2020), with participants predominantly drawn from monolingual language backgrounds. While some studies have explored bilingual or multilingual exposure, these remain largely situated within Western settings (Lim et al., 2025). Given these gaps, a systematic review examining the effects of bilingual or multilingual interventions for children with ASD across different global regions, including Western, Asian and other multilingual contexts such as South America and Africa is warranted. Specifically, it will compare language, social and other developmental outcomes related to school/workplace readiness for ASD children who receive no multilingual interventions. This dataset contains preregistration documents for the systematic review (under embargo until April 2026).