Maternal Migration, Prenatal Stress and Child Autistic Traits: Insights From a Population-Based Cohort Study

OBJECTIVE There is emerging evidence for an increased prevalence of autism in children of mothers with a migration background. To date, the mechanisms underlying this relationship are poorly understood. We investigated whether prenatal stress exposure mediates the association between maternal migration and child autistic traits, assessing 1st and 2nd generation migrant mothers in the Netherlands and their children. METHOD The study was embedded in the prospective population-based Generation R cohort. Of the 4,727 participants, 1,773 mothers (38%) had a migration background. Prenatal stress was assessed using questionnaires related to stressful life events, family functioning, self-esteem, long-lasting difficulties, symptoms of psychopathology, social support and perceived discrimination. Autistic traits were measured at age 6 years with the parent-reported Social Responsiveness Scale exclusively. Longitudinal multiple mediation analyses were performed. Analyses were stratified by migration origin (Europe and Outside Europe) due to differences in migration characteristics. RESULTS Maternal migration background was associated with more experienced stress and with higher child autistic trait scores (Europe: M=0.42, SD=0.25. Outside Europe: M=0.50, SD=0.24) compared to no migration background (Netherlands: M=0.38, SD=0.23, both p<.01). Prenatal stress, especially perceived discrimination and maternal psychopathology, accounted for up to half of the total effect of maternal migration, which remained after adjusting for sociodemographic factors (Bindirect=0.035, 95%CI [0.027, 0.043], Btotal =0.074). CONCLUSION Stress during pregnancy mediated the association between maternal migration status and child autistic traits. Future research should focus on early interventions to assess whether reducing prenatal stress exposure among women with a migration background can result in lower offspring autistic traits.