Evaluation of the Association Between Prenatal Cannabis Use and Risk of Developmental Delay

Abstract

Objective

Conflicting results have arisen regarding the association between prenatal cannabis exposure and risk of parent-reported developmental delay in infancy. In certain instances, this literature has become outdated or failed to adjust for confounding variables. The current study aimed to determine if prenatal cannabis exposure was associated with a greater likelihood of risk of parent-reported developmental delay at 12 months of age in a contemporary cohort, while adjusting for common confounding variables.

Method

Participants (n = 10,695) were part of the Pregnancy During the COVID-19 Pandemic (PdP) study. A subset of the sample (n = 3,742) provided a parent-report developmental assessment, the Ages and Stages Questionnaire, Third Edition (ASQ-3), of their infant at 12 months old. Sociodemographic differences between participants who reported cannabis use (CU+ group) and those who did not (CU− group) were analyzed. To address potential heterogeneity between CU+ and CU− groups, propensity score weighting was used. G-computations were performed to analyze the association between outcome variables (gestational age, birth weight, and risk of parent-reported developmental delay) and prenatal cannabis exposure. Weighted linear or quasi-binominal logistic regression models were used, with differences of averages and odds ratios reported.

Results

Participants in CU+ and CU− groups significantly differed on all sociodemographic variables. Prenatal cannabis exposure was not associated with any birth outcomes (ps > .05). Prenatal cannabis exposure was significantly associated with risk of parent-reported developmental delay on the communication domain (p = .02). This finding was not significant after adjusting for multiple comparisons. No additional domains were significantly associated (ps > .05).

Conclusion

Prenatal cannabis exposure was associated with increased odds of delay on the communication domain before adjusting for multiple comparisons. No other domains were significantly associated with increased odds of delay. These findings should not be interpreted as suggesting that consuming cannabis products during pregnancy is safe for infant development. Further, the analysis was performed using data from a longitudinal sample that was not specifically created to address this question, but was leveraged to explore these outcomes. Additional studies that are specifically designed to examine these outcomes are needed.

Plain language summary

Prior research has been conflicting regarding the link between prenatal cannabis exposure and developmental delays. Secondary analysis of data from the cross-Canada Pregnancy During the COVID-19 Pandemic (PdP) study showed significant sociodemographic differences between individuals who did and did not use cannabis during pregnancy. However, prenatal cannabis exposure was not associated preterm birth or birth weight. Prenatal cannabis exposure was nonsignificantly associated with risk of parent-reported delays in communication. Future research should address these questions and include considerations of quantity of cannabis used.

Diversity & Inclusion Statement

We worked to ensure that the study questionnaires were prepared in an inclusive way. We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. The author list of this paper includes contributors from the location and/or community where the research was conducted who participated in the data collection, design, analysis, and/or interpretation of the work. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented sexual and/or gender groups in science.