Cannabis-involved pregnancy hospitalizations more than doubled in Colorado after legalization
Cannabis-involved pregnancy hospitalizations in Colorado increased from 429 to 1,210 (13.2 to 55.7 per 10,000 live births) between 2011 and 2018, with recreational dispensary access associated with the increase.
Quick Facts
What This Study Found
Cannabis-involved pregnancy hospitalizations increased more than two-fold from 2011-2018. Increasing recreational dispensaries were associated with increases in hospitalizations (IRR 1.02). Counties with no prior medical cannabis exposure had greater increases than counties already exposed.
Key Numbers
Hospitalizations increased from 429 to 1,210. Per 10,000 live births: 13.2 to 55.7. Mean per county: 1.7 to 4.7. Recreational dispensary association: IRR 1.02. Previously unexposed counties had greater increases.
How They Did This
Retrospective cohort study of pregnancy-related hospitalizations co-coded with cannabis diagnoses in Colorado (2011-2018). Poisson regression assessed association between county-level recreational dispensary density and hospitalization rates, controlling for baseline medical dispensary exposure.
Why This Research Matters
The sharp increase in cannabis-involved pregnancy hospitalizations after legalization raises important public health questions about how legalization affects cannabis use during pregnancy.
The Bigger Picture
This is one of the first studies to directly link dispensary access to cannabis-involved pregnancy hospitalizations, providing data for the ongoing debate about legalization and maternal health.
What This Study Doesn't Tell Us
Administrative data may overcount if cannabis screening became more routine. Cannot distinguish between cannabis causing the hospitalization versus incidental detection. The IRR of 1.02, while significant, is small per dispensary.
Questions This Raises
- ?Is the increase due to more cannabis use during pregnancy, more screening/detection, or both?
- ?Are pregnancy outcomes worse in cannabis-involved hospitalizations?
- ?Would educational interventions at dispensaries reduce use during pregnancy?
Trust & Context
- Key Stat:
- Hospitalizations increased from 13.2 to 55.7 per 10,000 live births
- Evidence Grade:
- Moderate: population-level administrative data with natural experiment design, but potential confounding from increased screening.
- Study Age:
- Published in 2022.
- Original Title:
- Cannabis legalization and cannabis-involved pregnancy hospitalizations in Colorado.
- Published In:
- Preventive medicine, 156, 106993 (2022)
- Authors:
- Wang, George Sam(15), Buttorff, Christine(4), Wilks, Asa(4), Schwam, Daniel, Metz, Torri D, Tung, Gregory, Pacula, Rosalie Liccardo
- Database ID:
- RTHC-04290
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Did cannabis use during pregnancy really increase that much?
The data show a more than two-fold increase in cannabis-involved pregnancy hospitalizations, but some of this increase could reflect more routine cannabis screening rather than more actual use.
Did counties without previous dispensaries see bigger increases?
Yes. Counties with no prior medical cannabis dispensary exposure had greater increases than counties that already had medical dispensaries, suggesting the newly available recreational market influenced use among pregnant individuals.
Does this mean cannabis harms pregnancies?
This study measured hospitalizations with a cannabis diagnosis code, not pregnancy outcomes. Whether the cannabis involvement caused harm requires separate investigation.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-04290APA
Wang, George Sam; Buttorff, Christine; Wilks, Asa; Schwam, Daniel; Metz, Torri D; Tung, Gregory; Pacula, Rosalie Liccardo. (2022). Cannabis legalization and cannabis-involved pregnancy hospitalizations in Colorado.. Preventive medicine, 156, 106993. https://doi.org/10.1016/j.ypmed.2022.106993
MLA
Wang, George Sam, et al. "Cannabis legalization and cannabis-involved pregnancy hospitalizations in Colorado.." Preventive medicine, 2022. https://doi.org/10.1016/j.ypmed.2022.106993
RethinkTHC
RethinkTHC Research Database. "Cannabis legalization and cannabis-involved pregnancy hospit..." RTHC-04290. Retrieved from https://rethinkthc.com/research/wang-2022-cannabis-legalization-and-cannabisinvolved
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.