Prevalence of autism according to maternal immigrant status and ethnic origin

Abstract

These results are consistent with the maternal vitamin D insufficiency hypothesis. Neurobiological studies are warranted to document the effect of maternal vitamin D insufficiency during pregnancy on the foetal brain and the window of vulnerability. This review stresses the importance of monitoring vitamin D levels in pregnant women, especially those who are immigrant, dark-skinned or veiled, and the urgency of randomized controlled trials.

Are different subtypes of autism spectrum disorders associated with different factors?

“…But the analysis distinguishing ASD subtypes showed that black children were more likely to be diagnosed with autistic disorder, but less likely with Asperger disorder. These results are in line with a review of studies conducted in the USA which found a higher risk for the more severe subtypes of ASD (autism strictly defined or associated with MR) in black than in white children, but a lower risk for less severe subtypes (Asperger disorder, PDD-NOS, autism without MR) (8).…”

Learning Problems in Children of Refugee Background: A Systematic Review

“…4 Most studies examined outcomes in adolescent cohorts, there were few studies on primary school aged children and only a single study involving preschool children, which is concerning given the importance of early identification for effective intervention. 43 Notably, no studies reported the prevalence of autism spectrum disorder, despite higher rates in other immigrant populations [44][45][46][47] and a postulated association with low vitamin D levels, 48 which is well described in resettled refugee populations. 49 Similarly, there were no studies on language impairment, dyscalculia, or dyslexia, and only 1 study examined any contribution from sensory impairment.…”

Environmental factors associated with autism spectrum disorder: a scoping review for the years 2003–2013

“…For example, maternal foreign birthplace and/or ethnicity were used as proxies for vitamin D concentration, based on the possibly inaccurate assumption that women in these categories would have darker skin pigmentation, affecting their vitamin D concentrations. 233 More direct evidence for an association between vitamin D and ASD by direct exposure measurements is required.…”

“…It has been suggested that migration may play a role in the etiology of ASD, because of increased autism prevalence rates among immigrants in northern European countries, and because immigrants with dark skin are more prone to vitamin D deficiency due to their skin pigmentation. 233 However, both a small case-control study 234 and a recent Australian prospective cohort study 235 found no significant association between maternal serum vitamin D levels and ASD or a majority of autistic-like traits in their offspring. Furthermore, a systematic review concluded that there was inadequate support for an association, and that more population-based longitudinal studies are needed, given the plausible biological evidence.…”