Pet Flea and Tick Control Exposure During Pregnancy and Early Life Associated with Decreased Cognitive and Adaptive Behaviors in Children with Developmental Delay and Autism Spectrum Disorder.

Researchers studied whether household bug sprays and pet flea/tick products affect children's development. They looked at 1,533 children, including those with autism and developmental delays. They found that using flea and tick soaps, shampoos, and powders on pets during a child's second year was linked to lower thinking and daily living skills in autistic children. Similar products used during pregnancy may affect children with developmental delays.

Typically developing children showed no effects.

This CHARGE study examined associations between household insecticide exposure and neurodevelopment in 1,533 children aged 24-60 months, including those with autism spectrum disorder (ASD), developmental delay (DD), and typical development (TD). Researchers analyzed exposure to indoor, outdoor, and pet insecticides from three months pre-conception to age two, assessing cognitive and adaptive functioning using standardized measures. Results showed that flea/tick soaps, shampoos, and powders used during the second year of life were significantly associated with lower cognitive and adaptive scores in children with ASD after multiple comparison correction. Flea/tick skin treatments during early pregnancy showed associations with reduced scores in the DD group, though significance was lost after correction.

No associations were observed in typically developing children, suggesting differential vulnerability in neurodivergent populations.

Findings suggest household insecticide exposure, particularly pet flea/tick products, may represent modifiable environmental risk factors for cognitive development in children with ASD and DD. Clinicians should consider discussing safer pest control alternatives with families of neurodivergent children.

Study design not specified in abstract. Exposure data based on parental report, which may introduce recall bias. Multiple comparison corrections reduced significance of some findings. Causality cannot be established from this observational study design.

Approximately 18% of U.S. children experience cognitive and behavioral challenges, with both genetic and environmental contributors. We examined if household insecticides, particularly those used in and around the home and on pets, are associated with neurodevelopmental changes. Data were from children aged 24-60 months in the CHARGE study with the following classifications: autism spectrum disorder (ASD,= 810), developmental delay (DD,= 192), and typical development (TD,= 531). Exposure to indoor, outdoor, and pet insecticides was reported for the period from three months pre-conception to the second birthday.

Cognitive and adaptive functioning were assessed using the Mullen Scales of Early Learning and Vineland Adaptive Behavior Scales. Linear regression was used to evaluate associations by diagnostic group, adjusting for confounders. Flea/tick soaps, shampoos, and powders used during year two were significantly associated with lower cognitive and adaptive scores in children with ASD after FDR correction. Flea/tick skin treatments in early pregnancy were associated with reduced scores in the DD group, though not significant after correction, especially when used with high frequency.

No associations were observed in TD children. These findings underscore the need to examine early-life exposure to non-agricultural insecticides as modifiable risk factors for neurodevelopment.