Maternal Cannabis Use in Pregnancy and Autism Spectrum Disorder or Attention-Deficit/Hyperactivity Disorder in Offspring

A meta-analysis of 13 observational studies found gestational cannabis exposure associated with small increased risks of ASD (RR 1.30) and ADHD (RR 1.13), though the ADHD finding may reflect publication bias. A larger cohort study showed cannabis use disorder during pregnancy was associated with substantially increased ASD risk (RR 3.02–3.21), though the authors acknowledge limitations including potential genetic and environmental confounding.