Associations of Characteristics of Parental Country of Birth with Autism Spectrum Disorder and Early Learning Delay Among Immigrant Populations in the US: Findings from the Study to Explore Early Development.

Our objective was to explore associations between human development and gender inequality indices in the birth country of immigrant parents and child risk for autism spectrum disorder (ASD) alone, ASD with early learning delay (ELD), and ELD alone. We used data from a multi-site case-control study that recruited US-born children aged 2-5 years with ASD and developmental delays through clinical and educational sources and a population control group through vital records. We defined ELD as Mullen Scales of Early Learning composite score ≤ 70. Parental birth country and socio-demographics were collected via interview. Associations between United Nations Development Programme human development (low-medium/high-very high), inequality-adjusted human development (< 50th /≥50th percentile) and gender inequality (≥ 50th /<50th percentile) indices with ASD/ELD categories were assessed with multinomial logistic regression. Effect modification by having a non-US born mother vs. non-US-born father only, and age at parental immigration was assessed. Odds for ASD + ELD were higher if parents immigrated from a country with lower human development, both overall and adjusted for inequality, and more gender inequalities. None of the indices were significantly associated with ASD alone nor ELD alone. Having a non-US-born mother vs. non-US-born father only and parental age at immigration did not modify these relationships. This study supports evidence that health, well-being and equality conditions in the birth country of immigrant parents may influence ASD + ELD risk but not ASD alone or ELD alone. Results can be used to support families immigrating from countries with low human development and high gender inequality indices and their US-born children.