Importance: Cannabis use during pregnancy is increasingly common in the US and may affect the development and behavior of preschool-aged children.
Objective: To prospectively investigate the association of prenatal cannabis exposure with executive function and aggressive behavior at age 5 years.
Design, setting, participants: This cohort study was conducted from 2016 through 2020. Data analysis was conducted from 2022 through 2024. Patients aged 16 through 50 years who were able to communicate in English and intended to deliver at the Ohio State University Wexner Medical Center were enrolled in a pregnancy research repository. Participants (n = 355) who gave consent for future contact and whose child(ren) was presumed to be alive were invited to participate again at child age 5 years (children born May 25, 2010, through February 7, 2016) and 250 children participated (70%).
Exposure: Cannabis exposure was measured prospectively by urine toxicology, maternal self-report, and obstetric record abstraction.
Main outcomes and measures: Executive function and aggressive behavior, measured via multimodal assessment by staff masked to exposure status. Outcomes were chosen a priori.
Results: Of 250 children, 80 were exposed to cannabis (32%). Use of tobacco, other drugs, and alcohol during pregnancy was common (22% to 39% each). Most families were living in poverty. There were 155 children who were Black/African American, non-Hispanic (62%); 11 were Hispanic (4%); 34 indicated more than one race or another race, non-Hispanic (14%); and 50 were White, non-Hispanic (20%). Age-corrected standard scores for children's attention and inhibitory control (National Institutes of Health Toolbox) were about 0.4 SDs lower for those exposed to cannabis compared with unexposed (β = -6.1 points; 95% CI, -10.8 to -1.4), following propensity score weighting and adjustment for confounders. Exposed children also exhibited poorer task-based planning ability and more observed aggression. Caregiver ratings of executive function and behavior and laboratory assessments of other aspects of executive functioning showed no differences by exposure status.
Conclusions and relevance: Results from this contemporary US cohort where prenatal cannabis exposure was common and indicated that exposed children exhibited some differences in aspects of executive function and behavior relevant to long-term academic success and adaptive functioning. These results may be considered in refining clinical recommendations regarding cannabis use during pregnancy.