Gender on the Spectrum: Prevalence of Gender Diversity in Autism Spectrum Disorder—A Systematic Review and Meta-Analysis

Background: The intersection of Autism and Gender Diversity (GD) is an emerging field of research. While prior studies have primarily focused on autistic traits within gender-diverse populations, limited evidence exists on the prevalence and characteristics of GD among individuals with a confirmed Autism Spectrum Disorder (ASD) diagnosis. This study aims to fill this gap through a systematic review and meta-analysis, offering comprehensive insights into the prevalence of GD in autistic individuals and the factors influencing this intersection. Methods: We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 guidelines. We searched for studies published between 2013 and 2023 in four databases. Inclusion criteria focused on studies assessing GD in children and adult participants with a formal ASD diagnosis based on Diagnostic and Statistical Manual of Mental Disorders , Fifth Edition, criteria. We used random-effects models to estimate prevalence rates, and subgroup analyses explored potential influencing factors, including age, gender assigned at birth, type of GD assessment, ASD diagnosis methodology, and primary objective of the study. Results: From 7133 identified reports, we deemed 24 studies suitable for the systematic review, with 14 meeting all eligibility criteria for meta-analysis, representing 3894 autistic participants. We estimated the pooled prevalence of GD at 7.37% (95% confidence interval CI: 4.45–11.98). Subgroup analyses revealed no significant impact of age, type of GD assessment, or diagnostic methodology of ASD on GD prevalence. Although we found a higher prevalence of GD among individuals assigned female at birth (14.54%) compared with those assigned male at birth (8.15%), the difference was not statistically significant. However, studies explicitly addressing GD reported statistically higher GD rates (13.71%) compared with those with other primary objectives (4.71%). Non-binary identities appeared particularly prevalent, but we did not underexplore it due to variability in GD definitions across studies. Conclusion: This study highlights a notable prevalence of GD among autistic individuals, emphasizing the need for inclusive definitions and diagnostic process. Understanding this intersection is crucial for enhancing support services and ensuring equitable access to gender-affirming care for neurodiverse populations.