Policymakers should be cautious about enacting policies requiring mandatory warning signs (MWS) for cannabis use. Research has found adverse health consequences associated with MWS-cannabis and that people lack trust in information on signs.
Background: Policies on Mandatory Warning Signs for Cannabis Use During Pregnancy
Several states that have legalized recreational cannabis have enacted policies mandating that signs warning about harms from using cannabis during pregnancy (MWS-cannabis) are to be posted in places where cannabis is sold. MWS-cannabis policies provide pregnancy-specific warnings about cannabis use in an effort to increase pregnant people's awareness about the risks of use and thus lead them to stop using during pregnancy.
However, the idea that MWS reduce substance use is not well-supported by existing evidence. Further, previous research has found MWS for alcohol during pregnancy (MWS-alcohol) was associated with increases in adverse birth outcomes. The Warning Sign Evidence, Evaluation and Dissemination (WEED) Study, a multi-pronged research project, sought to understand the public health impact of MWS for cannabis use and explore people's perspectives and preferences regarding MWS-cannabis.
Findings: Policies Mandating Posting of MWS for Cannabis Use Could Be Harmful
Similar to findings for MWS for alcohol use during pregnancy, enacting MWS for cannabis use during pregnancy is related to increases in adverse birth outcomes, specifically to a higher proportion of babies born low birthweight. Additionally, living in a state a MWS-cannabis policy is not associated with decreases in use but is associated with believing that people should be punished and stigmatized for their use.
In qualitative interviews with pregnant and recently pregnant people who use cannabis, participants reported mostly negative views on MWS-cannabis, suggesting that messages that push abstinence and warn about punishment may be stigmatizing and discourage people from seeking care. When reacting to specific messages, participants preferred messages that are evidence-based, clear, specific, and aligned with autonomous decision-making. More work is needed to develop health information resources that meet the needs of people who use cannabis in pregnancy without increasing stigma.
The research team recently recorded a webinar (available upon request) about the study’s implications for cannabis policy, and how research can better explore pregnant people's perspectives on MWS.