Information regarding the impact of cannabis on fertility is somewhat confusing and contradictory. This highlights the need for more research on the subject. To meet this need, a new study has been published on the effect of cannabis use on in-vitro fertilisation (IVF).
Results showed no difference in the IVF success rate between cannabis users and non-users, indicating that getting high doesn’t hinder fertility in any way[i].
Cannabis Doesn’t Jeopardise IVF
The study authors analysed the IVF outcomes of 722 patients at a single Canadian fertility centre. Just under ten percent identified as cannabis users. Crucially, those who claimed to smoke, vape, or eat weed had the same implantation rate as those who had never used cannabis.
Even more importantly – and somewhat surprisingly – cannabis users undergoing IVF had a higher ongoing pregnancy rate than non-users. Overall, 35.2 percent of users went on to become pregnant due to their treatment, compared to 29.1 percent of non-users.
Looking a little deeper, the researchers analysed several fertility-related measures such as ovarian response, the efficiency of fertilisation, and early embryonic development. They also assessed sperm quality in male partners. They found absolutely no differences in these reproductive outcomes between cannabis users and non-users.
Summing up this finding, the study authors write that “the results may provide some reassurance for the lack of any demonstrable detrimental effects of cannabis consumption on IVF outcomes.”
They go on to explain that numerous similar studies have been conducted in recent years, all of which have returned similar results. For instance, they point to a large-scale project that followed thousands of couples attempting to conceive between 2002 and 2015. Ultimately, the authors “were not able to detect any difference in the length of the time to pregnancy between either male or female cannabis users and non-users regardless of the frequency of use.” [ii]
Cannabis, Sperm and IVF
In addition to assessing the fertility of female cannabis users undergoing IVF, the researchers also looked at the sperm quality of men whose partners sought treatment. Much to their surprise – and delight – they found that men who used pot had better sperm quality and higher semen volume than those who didn’t.
As this is an observational study, the authors are unable to explain why this is the case. However, they point out that this finding is not a one-off. For example, a study from 2019 concluded that couples undergoing IVF were more likely to have a baby if the male partner was a cannabis user[iii].
Though the reasons behind this advantage are unclear, animal studies have shed light on the harmless nature of cannabinoids on male fertility. Recent research on mice, for instance, revealed that regular THC injections do not affect sperm motility or concentration. When mouse sperm treated with cannabis was used for IVF, it was just as fertile as animals who’d not received any weed[iv]. Obviously, more research is needed before drawing any rock-solid conclusions regarding the impact of cannabis on IVF and fertility in general. However, as the picture becomes a little clearer, most of the evidence suggests there’s no cause for concern.
[i] Har-Gil E, Heled A, Dixon M, Ahamed AM, Bentov Y. The relationship between cannabis use and IVF outcome—a cohort study. Journal of Cannabis Research. 2021 Dec;3(1):1-7. – https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-021-00099-5
[ii] Kasman AM, Thoma ME, McLain AC, Eisenberg ML. Association between use of marijuana and time to pregnancy in men and women. Findings from the National Survey of Family Growth. Fertil Steril. 2018;109(5):866–71 – https://linkinghub.elsevier.com/retrieve/pii/S0015028218300153
[iii] Nassan FL, Arvizu M, Minguez-Alarcon L, Williams PL, Attaman J, Petrozza J, et al. Maijuana smoking and markers of testicular function among men from a fertility centre. Hum Reprod. 2019b;34(4):715–23. https://doi.org/10.1093/humrep/dez002
[iv] Lopez-Cardona AP, Ibarra-Lecue I, Laguna-Barraza R, Perez-Cerezales S, Uriguen L, Agirregoitia N, et al. Effect of chronic THC administration in the reproductive organs of male mice, spermatozoa and in vitro fertilization. Biochem Pharmacol. 2018;157:294–303. https://doi.org/10.1016/j.bcp.2018.07.045