Is the association between mothers’ autistic traits and childhood autistic traits moderated by maternal pre-pregnancy body mass index?

Abstract

Background: Previous studies showed that there is a positive association between mothers’ and children’s autistic traits. We also tested if this association is more pronounced in mothers with a higher pre-pregnancy body mass index (BMI). Method: The study was embedded in two cohorts with information available for 4,659 participants from the Generation R and for 179 participants from the Cambridge Ultrasound Siblings and Parents Project (CUSP) cohort. In both cohorts, maternal autistic traits were assessed using the short form of the Autism Spectrum Quotient (AQ), and information about maternal height and weight before pregnancy was obtained by questionnaire. Child autistic traits were assessed with the short form of Social Responsiveness Scale (SRS) in Generation R (M = 13.5 years), and with the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in the CUSP cohort (M = 1.6 years). Result: Higher maternal autistic traits were associated with higher autistic traits in toddlerhood (CUSP cohort; β = 0.20, p < 0.01), in early childhood (Generation R; β = 0.19, p < 0.01), and in early adolescence (Generation R; β = 0.16, p < 0.01). Maternal pre-pregnancy BMI were associated to child autistic traits in Generation R (β = 0.03, p < 0.01). There was no significant moderating effect of maternal pre-pregnancy BMI for the association between autistic traits of mothers and children both in the Generation R cohort and in the CUSP cohort. In addition, child autistic traits scores were significantly higher in mothers who were underweight and in mothers who were overweight compared to mothers with a healthy weight. Conclusion: We confirm the association between maternal and child autistic traits in toddlerhood, early childhood, and early adolescence. Potential interacting neurobiological processes remain to be confirmed.