Miscarriage rates are rising—is this unexpected habit to blame?
By Elizabeth Pratt | Fact-checked by Barbara Bekiesz | Published March 3, 2025
Industry Buzz
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“In the United States, because marijuana is rated as a class-five drug, […] most of the studies or information we have is essentially anecdotal or by observational studies.” — G. Thomas Ruiz, MD, board-certified OB/GYN at MemorialCare Orange Coast Medical Center in Fountain Valley, CA
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“[It’s] plausible that marijuana could be damaging to sperm quantity and quality and therefore could be associated with early miscarriage risks.” — Ilina Pluym, MD, OB/GYN and assistant clinical professor at David Geffen School of Medicine, UCLA
It’s legal for recreational use in 24 states, two territories, and the District of Columbia.[1] But what impact is marijuana having on miscarriage rates?
Experts say research in the area is limited.
“In the United States, because marijuana is rated as a class 5 drug, it’s very hard to get marijuana to do objective research, so most of the studies or information we have is essentially anecdotal or by observational studies,” G. Thomas Ruiz, MD, board-certified OB/GYN at MemorialCare Orange Coast Medical Center in Fountain Valley, CA, tells MDLinx. “The one thing we do know that seems to be true is that with fetal development, THC tends to affect cerebral and neural development.”
Warning for male partners who use marijuana
Research suggests that in heterosexual couples, women who have a male partner who uses marijuana 1 or more times per week are more likely to miscarry when compared with women whose male partners don’t use marijuana, or use marijuana once a week or less.[2]
The same research found that the link between marijuana use in males and miscarriage persisted even if the female partners themselves never used marijuana.
Dr. Ruiz says this highlights how sperm is impacted by a man’s overall health.
“A man’s sperm count is directly related to their health. If a male is unhealthy or has a chronic medical condition, the sperm count will go down. So you can use that to kind of extrapolate that in this situation; semen, based on that data, may be more sensitive to some environmental factors, and that would be like alcohol abuse [or] marijuana abuse,” he says.
Marijuana can be harmful during conception
More research is needed to determine the complete impact of marijuana on pregnancies and miscarriage, but existing research does suggest use of marijuana can be detrimental.
“There have been studies showing increased miscarriage risks in women using marijuana during conception. This seems plausible given cannabinoid effects on implantation of the embryo,” Ilina Pluym, MD, OB/GYN and assistant clinical professor at the David Geffen School of Medicine at UCLA, tells MDLinx.
Dr. Ruiz argues it’s important that all couples undergo preconception counselling, and that physicians make them aware of anything that could increase the likelihood of miscarriage, including use of marijuana for either partner.
Once a male stops taking marijuana, it can take months for his sperm count to return to a healthy level.
“It actually takes about 3 months for a male sperm count to normalize,” Dr. Ruiz says.