Early indicators of autism in young girls: A systematic review

Sex differences in autism may contribute to the delayed detection and diagnosis of autistic girls. This systematic literature review aimed to support the detection of autistic girls in early childhood (up to and including six years of age) by examining how autism presents in young girls. This registered review examines the published literature from 5 databases (PsycArticles, PsycINFO, CINAHL, EMBASE, MEDLINE) from inception to 2024. The inclusion criteria for the search was qualitative, quantitative, or mixed-methods studies that reported on behaviours related to autism which highlight sex or gender differences in the presentation of autism. Following the initial screening of 989 publications, 12 met the final inclusion criteria. Findings were inconsistent, suggesting that autistic boys and autistic girls exhibit more similarities than differences in their autistic expression during early childhood. The number of studies was low; as such, it is difficult to draw definitive conclusions. Consequently, rigorous research is needed to determine potential sex/gender differences in autism presentation, the validity of measurement tools in assessment more broadly, and reflection on what is being measured in terms of autism diagnostic tools and attributed behaviours. Our understanding of autism will no doubt evolve as autistic adults who were not identified in childhood continue to increase. The active involvement of autistic individuals in rigorous, transparent research and scrutiny of assessment methods will significantly advance early identification to provide support and awareness.