A recent study published in JAMA Network Open surveyed 2063 pregnant or recently pregnant people living in US states with legalized recreational cannabis, 585 of whom reported using cannabis during their pregnancy (CUDP). Researchers from the University of California, San Francisco supported by a grant from the California Department of Cannabis Control reported that among those who used cannabis during their pregnancy, living in a state with warning signs about the use of cannabis during pregnancy was associated with beliefs that cannabis use during pregnancy was safe, and that those who used cannabis during pregnancy should not be punished. Among people who did not use cannabis before or during pregnancy, living in a warning-signs state was associated with beliefs that use was not safe, and with greater support for punishment regarding pregnant people’s cannabis use.
"Considerable questions remain as to why warning signs for substance use during pregnancy may have unintended adverse consequences," the study's authors write. "One possibility is that warning signs increase fears of punishment and thus influence pregnant people to avoid prenatal care. Another is that warning signs may lead people to believe their substance use has already irreversibly harmed their baby and thus it is too late to stop use. From the larger health communications literature, people who use cannabis could experience message fatigue and tune out or distrust information in messages."