Autism and immigration, is there a link? Results from a Manitoba Study.

Objectives: To examine a possible association between parental immigration and autism spectrum disorder (ASD) in Manitoba, Canada. Methods: Electronic medical records of children diagnosed with ASD between 2016 and 2021 at Manitoba's only publicly funded referral site for ASD evaluation in children ≤6 years of age were reviewed. Children born in or outside of Canada whose parents/guardians (one or both) were foreign-born were identified to have 'immigrant' parents. The proportion of Manitoba's immigrant population (including non-permanent residents) was obtained from 2016 to 2021 Census data and compared to the proportion of children diagnosed with ASD who had immigrant parent(s). Descriptive statistics were used to compare the characteristics of children with ASD born to immigrants versus non-immigrant parents. Results: Among 1858 children diagnosed with ASD during the study period, 669 (36%) had immigrant parents. This proportion was greater than the proportion of immigrants (and non-permanent residents) living in Manitoba in 2016: 243,835/1,278,365 (19%, P < 0.001) and 2021: 291,910/1,342,153 (21.7%, P < 0.001). Those with immigrant parents had a lower rate of family history of ASD (16.3% versus 33.3% P < 0.001), and associated neurologic comorbidities (4.2% versus 6.4% P: 0.047). There were no statistical differences in rates of preterm birth (15.5% versus 12.36 P: 0.152) or use of Autism Diagnostic Observation Schedule-2 in diagnostic approach (30.3% versus 33% P: 0.321) between groups. Conclusions: There is an over-representation of immigrant families among young children diagnosed with ASD in Manitoba. Further studies are needed to understand mechanisms that may play a role in this association.