Cannabis use showed no detectable effect on IVF outcomes in this cohort
Among 722 IVF patients, cannabis users (9.4%) had similar implantation and pregnancy rates as non-users, with no significant differences in any measured outcome.
Quick Facts
What This Study Found
Implantation rates were virtually identical: 40.74% for users vs. 41.13% for non-users. Ongoing pregnancy rates were 35.2% for users vs. 29.1% for non-users (not statistically significant). No significant differences were found in oocyte yield, fertilization rate, peak estradiol, sperm quality, or embryo quality.
Key Numbers
722 patients total. 68 (9.4%) cannabis users, most light users. Implantation rate: 40.74% (users) vs. 41.13% (non-users). Ongoing pregnancy rate: 35.2% vs. 29.1% (not significant). No significant differences in any other outcome.
How They Did This
Retrospective cohort study from a single Canadian IVF center. Of 722 non-donor IVF patients, 68 (9.4%) self-reported cannabis use (most described as light use). Compared IVF outcomes between users and non-users using Mann-Whitney, chi-square, and Kruskal-Wallis tests.
Why This Research Matters
Cannabis use during fertility treatment is a growing concern as legalization expands. This study provides early reassurance that light cannabis use may not significantly harm IVF outcomes, though the evidence is far from definitive.
The Bigger Picture
The cannabis-fertility question remains open. While this study found no detectable harm, the small user sample (68 patients) and self-reported use data mean subtle effects could have been missed. The lack of harm signal is notable but not conclusive.
What This Study Doesn't Tell Us
Retrospective design. Small user group (68 patients). Self-reported cannabis use likely underestimates true prevalence. Most users were light users, so heavy use effects remain unknown. Single center.
Questions This Raises
- ?Would heavier cannabis use show different IVF outcomes?
- ?Are cannabis users underreporting in clinical settings?
- ?Would a prospective study with biological verification of use reveal effects missed here?
Trust & Context
- Key Stat:
- No significant difference in any IVF outcome between users and non-users
- Evidence Grade:
- Small user sample within a single-center retrospective study. Self-reported cannabis use is a significant limitation.
- Study Age:
- 2021 study from a Canadian IVF center following legalization.
- Original Title:
- The relationship between cannabis use and IVF outcome-a cohort study.
- Published In:
- Journal of cannabis research, 3(1), 42 (2021)
- Database ID:
- RTHC-03189
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Did cannabis affect pregnancy rates in IVF?
No significant difference was found. Ongoing pregnancy rates were 35.2% for cannabis users and 29.1% for non-users, but this difference was not statistically significant.
Were most cannabis users in the study heavy users?
No. Most were self-described light users, which limits what this study can say about heavier use patterns.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-03189APA
Har-Gil, Eden; Heled, Ayala; Dixon, Marjorie; Ahamed, Abdul Munaf Sultan; Bentov, Yaakov. (2021). The relationship between cannabis use and IVF outcome-a cohort study.. Journal of cannabis research, 3(1), 42. https://doi.org/10.1186/s42238-021-00099-5
MLA
Har-Gil, Eden, et al. "The relationship between cannabis use and IVF outcome-a cohort study.." Journal of cannabis research, 2021. https://doi.org/10.1186/s42238-021-00099-5
RethinkTHC
RethinkTHC Research Database. "The relationship between cannabis use and IVF outcome-a coho..." RTHC-03189. Retrieved from https://rethinkthc.com/research/har-gil-2021-the-relationship-between-cannabis
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.