A 10-week walking intervention reduced prenatal cannabis use from 62.5% to 16.6% of participants, while also increasing physical activity and decreasing anxiety and depression — with 88% completing the program.
Pregnant individuals using cannabis, OB-GYNs, prenatal care providers, and substance use intervention researchers
What the researchers found
Prenatal cannabis use dropped from 62.5% at baseline to 16.6% by 36 weeks gestation; daily steps increased from 5,738 to 6,562; anxiety and depression significantly decreased; 88% retention rate with mean 5.8/6 sessions attended.
Why it matters
There are virtually no evidence-based interventions for prenatal cannabis use — this simple, low-cost walking program achieved remarkable reductions while also improving the mental health conditions that often drive cannabis use during pregnancy.
The numbers in context
16 participants; 88% completion; 5.8/6 sessions attended; cannabis use: 62.5% → 16.6%; daily steps: 5,738 → 6,562; no adverse events; significant anxiety and depression reductions.
How the study worked
Open pilot trial of a 10-week prenatal walking intervention with 16 pregnant individuals seeking to reduce cannabis use, using Fitbit tracking, 6 coaching sessions, and assessments of cannabis use, physical activity, and mental health.
What this study cannot tell us
Very small sample (n=16); no control group; open-label design; self-reported cannabis use; participants were motivated (self-selected to reduce use).
How to read the evidence
Small open pilot trial with no control group provides preliminary evidence only, but the effect size and retention are promising for a first-of-its-kind intervention.
When this study was published
Published in 2026, representing the first physical activity intervention specifically targeting prenatal cannabis use.
The bigger picture
The dual benefit — reducing cannabis use while improving the mental health symptoms that drive it — suggests physical activity addresses the root cause rather than just the behavior.
Questions still open
- Would these results hold in a larger controlled trial? Could similar interventions work for other prenatal substance use? Is the mechanism primarily through mood improvement or behavioral replacement?
Common questions
Can exercise help pregnant women stop using cannabis?
What did the walking program involve?
Read the original research
Feasibility and acceptability of a physical activity intervention to reduce prenatal cannabis use: results of an open pilot trial.
Frontiers in psychiatry, 17, 1729092
Citation
Battle, Cynthia L; Dreyer-Oren, Sarah E; Vijil Morin, Andrea; Hoyt, Morgan N; Metrik, Jane; Abrantes, Ana M. (2026). Feasibility and acceptability of a physical activity intervention to reduce prenatal cannabis use: results of an open pilot trial.. Frontiers in psychiatry, 17, 1729092. https://doi.org/10.3389/fpsyt.2026.1729092
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