States with legal recreational cannabis retail sales saw a 5 percentage point increase in binge drinking during pregnancy, and pregnant women in those states were twice as likely to binge drink.
Pregnant women, OB-GYNs, public health officials, policymakers considering cannabis legalization, and substance use researchers.
What the researchers found
Prevalence of binge drinking during pregnancy was 2.13 times higher in states with legal recreational cannabis retail sales. Difference-in-difference analysis showed implementation was associated with a 4.96 percentage point increase in binge drinking during pregnancy (95% CI: 1.22-8.70). Current drinking showed a non-significant increase.
Why it matters
This unexpected association suggests cannabis legalization may have unintended effects on other substance use during pregnancy. If the relationship is causal, it would mean cannabis policy changes are increasing risk of fetal alcohol spectrum disorders.
The numbers in context
Current drinking: 1.43x higher in legal states (95% CI: 1.18-1.73). Binge drinking: 2.13x higher (95% CI: 1.47-3.09). DID estimate: +4.96 percentage points for binge drinking (p<.05). Data span: 2011-2023 BRFSS.
How the study worked
Analysis of 2011-2023 Behavioral Risk Factor Surveillance System data. Adjusted prevalence ratios and difference-in-difference analyses compared drinking during pregnancy in states before/after implementing legal nonmedical cannabis retail sales versus states without implementation, controlling for demographics and policy variables.
What this study cannot tell us
Observational — cannot prove cannabis legalization causes increased drinking. Self-reported data likely underestimates both cannabis and alcohol use during pregnancy. Confounders may exist. Ecological fallacy risk (state-level associations don't prove individual behavior).
How to read the evidence
Large national dataset with rigorous difference-in-difference design, but observational nature limits causal claims.
When this study was published
Published in 2026, analyzing 2011-2023 data capturing the key period of U.S. cannabis legalization rollout.
The bigger picture
The mechanism is unclear — it could be normalization of substance use generally, lifestyle clustering effects, or confounding factors. Regardless, this finding suggests public health messaging about alcohol during pregnancy may need intensifying in states legalizing cannabis.
Questions still open
- What mechanism links cannabis legalization to alcohol use during pregnancy? Are women substituting or adding? Would enhanced prenatal screening in legal states help?
Common questions
Does cannabis legalization increase drinking during pregnancy?
Why would cannabis legalization affect alcohol use?
Read the original research
Alcohol Consumption During Pregnancy and State Implementation of Legal Nonmedical Cannabis Retail Sales in the U.S., 2011-2023.
American journal of preventive medicine, 70(2), 108105
Citation
Denny, Clark H; Deputy, Nicholas P; Abouk, Rahi; Dunkley, Janae D; Drake, Coleman; Kim, Shin Y; Pella, Michael; Roehler, Douglas R; Rose, Charles E. (2026). Alcohol Consumption During Pregnancy and State Implementation of Legal Nonmedical Cannabis Retail Sales in the U.S., 2011-2023.. American journal of preventive medicine, 70(2), 108105. https://doi.org/10.1016/j.amepre.2025.108105
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