Peripregnancy cannabis use linked to behavioral problems in children with autism symptoms but not in other children | Research

The takeaway

In a large US study, maternal cannabis use around pregnancy was associated with increased aggression, emotional reactivity, and sleep problems in children who showed autism symptoms, but these associations were largely absent in children without autism symptoms.

Parents and prospective parents, especially those with family history of autism spectrum disorder.

Behavioral effects of peripregnancy cannabis appeared only in children with ASD symptoms, not in other children

What the researchers found

Preconception-only cannabis use was associated with more aggressive behavior, emotional reactivity, and sleep problems specifically in children with ASD symptoms, but not in children without. Cannabis use during pregnancy was associated with attention and sleep problems in children with ASD symptoms, though these associations did not significantly differ by ASD status. Peripregnancy cannabis use was not associated with developmental abilities regardless of ASD symptoms.

Why it matters

This is among the first studies to examine whether the effects of prenatal cannabis exposure differ based on neurodevelopmental vulnerability. The finding that children with ASD symptoms are more affected suggests that cannabis exposure may interact with pre-existing neurodevelopmental risk factors.

The numbers in context

Sample: 2,734 with ASD symptoms, 3,454 without. Peripregnancy cannabis exposure: 6.0% (ASD group) vs 4.6% (non-ASD). Preconception-only use linked to aggression, emotional reactivity, sleep problems in ASD group only. Pregnancy use linked to attention and sleep problems in ASD group. No associations with developmental abilities in either group.

How the study worked

Children ages 30-68 months were evaluated with the Child Behavior Checklist and Mullen Scales of Early Learning. The sample included 2,734 children with ASD symptoms and 3,454 without. Cannabis use was assessed across three periods: peripregnancy (3 months preconception through delivery), pregnancy only, and preconception only. Peripregnancy exposure was reported for 6.0% of children with and 4.6% without ASD symptoms.

What this study cannot tell us

Observational study cannot establish causation. Cannabis use was self-reported and may be underestimated. ASD symptoms were identified through standardized assessments but do not equate to clinical diagnosis. Confounders including other substance use, socioeconomic factors, and genetic predisposition could explain the associations.

How to read the evidence

Large prospective cohort with standardized assessments and stratified analysis, though limited by self-reported cannabis use and potential confounding.

When this study was published

Published in 2025.

The bigger picture

The interaction between cannabis exposure and ASD vulnerability raises the possibility that cannabis does not uniformly affect all pregnancies but may pose particular risks when other neurodevelopmental risk factors are present. The fact that even preconception-only use showed associations in the ASD group is particularly intriguing and could reflect either biological priming or shared risk factors.

Questions still open

Why does preconception cannabis use show associations when use during pregnancy itself may not? Does cannabis exposure interact with genetic risk for ASD? Could the findings reflect shared genetic or environmental factors rather than a direct cannabis effect?

Common questions

Does cannabis cause autism?

This study did not find that cannabis use was associated with developmental abilities (a proxy for autism severity). Rather, it found that children who already had autism symptoms showed more behavioral problems if their mothers used cannabis around pregnancy.

Why did preconception-only use show effects?

This is unclear. Possible explanations include biological effects on egg maturation, epigenetic changes, or that preconception cannabis use is a marker for other lifestyle factors that affect child development.

Read the original research

Associations of maternal peripregnancy cannabis use with behavioral and developmental outcomes in children with and without symptoms of autism spectrum disorder: Study to Explore Early Development.

Autism research : official journal of the International Society for Autism Research, 18(1), 202-216

View on PubMed ↗Publisher’s paper ↗

Citation

DiGuiseppi, Carolyn; Crume, Tessa; Holst, Brady; Aiona, Kaylynn; Van Dyke, Julia; Croen, Lisa A; Daniels, Julie L; Friedman, Sandra; Sabourin, Katherine R; Schieve, Laura A; Wiggins, Lisa; Windham, Gayle C; Robinson Rosenberg, Cordelia. (2025). Associations of maternal peripregnancy cannabis use with behavioral and developmental outcomes in children with and without symptoms of autism spectrum disorder: Study to Explore Early Development.. Autism research : official journal of the International Society for Autism Research, 18(1), 202-216. https://doi.org/10.1002/aur.3284