Résumé
Background: autism spectrum disorder (ASD) is an early onset neurodevelopmental condition emerging from a complex interplay between gene expression and environment. Among environmental triggers, early nutrition and particularly breastfeeding status appear as interesting candidates. Indeed, recent meta-analysis suggested that breastfeeding is negatively associated with ASD emergence. Considering that breastfeeding has long been associated with better cognitive performances in neurotypical children we hypothesized that it could be associated with less severe clinical profiles of ASD children.Methods: we conducted an ancillary study based on the ELENA cohort (21multicEntric Longitudinal study of childreN with ASD) aimed at determining if breastfeeding initiation was associated with lower ASD clinical severity. Information about breastfeeding initiation, duration and exclusivity was collected from participating families and examined to the light of children’s with ASD clinical severity at inclusion measured by a set of standardized tools (Autism Diagnostic Observation Schedule-2 Calibrated Severity Score (ADOS-2 CSS), IQ, Vineland Adaptive Behavior Scales Second Edition (VABS-II), Social-Responsiveness Scale second version (SRS-2), Aberrant Behavior Checklist (ABC).Results: breastfed children had higher VABS-II daily living skills scores than never breastfed children (77.13 (±12.74) vs. 71.45 (±12.24) respectively, p=0.002) and tended to have higher VABS-II communication scores than never breastfed children (73.68 (±15.20) vs. 69.82 (±15.85) respectively, p=0.08). Breastfeeding status was not associated with VABS-II socialization score, SRS-2 total score, ADOS-2 CSS score, IQ and ABC scores. After adjustment for potential confounders, breastfed children scored higher than never-breastfed children on VABS-II daily living skills (adjusted β [95% CI]: 5.82 (1.75; 9.89), p=0.01; but not on VABS-II communication (p=0.26). Breastfeeding duration and exclusivity had no influence on clinical severity.Conclusions: in our sample of children with a confirmed ASD, breastfeeding was a protective developmental factor associated with better daily living skills than never-breastfed children. This protective value wasn’t observed for other clinical measures of severity. We found no effect of breastfeeding duration and exclusivity.