Some recent studies suggest that marijuana can negatively affect fertility in both men and women. Read the article to learn about the correlation between marijuana and fertility to get informed about the latest findings. Marijuana smoking makes sperm less fertile — even if the woman is the one who smokes it, a new study suggests. Learn about whether marijuana can cause infertility, including a review of research on marijuana's effects on women and men.
Three Ways Marijuana Can Affect Fertility
Some studies show that marijuana use negatively affects fertility in men and women. Many articles and physicians advise against using marijuana while trying to get pregnant to reduce the risks of infertility. Learn more about the warnings signs of infertility and discover how you can develop healthy habits to increase your chances of getting pregnant.
Anna Klepchukova, MD
1. Ovulation delay
Scientists aren’t sure exactly how THC affects the sexual function of women attempting to get pregnant. THC affects the hypothalamic-pituitary-gonadal (HPG) axis, which controls how your sex hormones interact. Continuous exposure to THC can inhibit the secretion of luteinizing hormone and prolactin from the pituitary gland in males and females. These hormones influence your chances of getting pregnant.
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In women, high THC doses interfere with the menstrual cycle and may delay or prevent ovulation. Cannabinoids inhibit the activity of the HPG axis, meaning that marijuana use decreases the production of several hormones and can inhibit sexual behavior — if your sex drive is down, this can also hinder your efforts to conceive.
Regular smokers may have an elevated risk of not ovulating at all. A 2016 report also suggests marijuana disrupts the menstrual cycle and can lead to anovulatory cycles (cycles without ovulation).
In general, it’s thought that marijuana can affect the production of luteinizing hormone in women. LH regulates testosterone production in men and stimulates female ovulation. When men smoke frequently, they tend to have lower levels of testosterone, and women who smoke frequently have less LH.
In addition to marijuana use, it’s important to examine other causes of late ovulation so you can put yourself in the best position for a successful pregnancy.
2. Lower sperm count
According to the Mayo Clinic, marijuana use can impair a man’s sperm count and ability to reproduce. Other research has suggested that marijuana is bad for men’s fertility.
However, a Harvard study surprisingly refutes those findings and states that there’s no evidence of harmful effects on fertility. In the study, researchers collected blood samples and semen from hundreds of volunteers at the Massachusetts General Hospital fertility clinic. In the study, which ran from 2000 to 2017, men were asked about their marijuana use. The results showed no correlation between marijuana use and male fertility.
Since there isn’t a conclusive determination on the subject, if you have a male partner who smokes, try to discourage him from doing so while you are trying to conceive — especially if his sperm count is low.
3. Deterioration of existing fertility problems
There’s no conclusive evidence that marijuana use causes infertility, but research has found that it can lower sperm count, increase anovulatory cycles, and disrupt the balance of hormones in the body that encourage pregnancy.
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Smoking Marijuana Lowers Fertility
Oct. 13, 2003 — Smoking marijuana makes sperm less fertile — even if the woman is the one who smokes it, a new study shows.
Marijuana-smoking college men volunteered for the study led by Lani J. Burkman, PhD, director of andrology at the University of Buffalo School of Medicine and Biomedical Sciences.
The smokers weren’t the only ones who got high. The drug affected their sperm, too. These stoned sperm party hard. And then? They burn out, researchers say.
“Marijuana-smoking men’s sperm are hyper. They are way out there,” Burkman tells WebMD. “They already have begun the vigorous swimming called hyperactivation. Sperm should be quiet at first. They should be waiting to be washed into cervix and approach the egg before they start hyperactivation.”
So the little guys are fast out of the gate, right? What’s wrong with a little head start?
“It is not a head start. They are going to blow it,” Burkman says. “They’re too fast, too early. Each individual sperm can maintain this swimming only so long, only several hours. Then it poops out. If it has run out of hyperactivation before it gets close to the egg, it will not fertilize. These sperm are going to burn out.”
Burkman announced the findings at this week’s meeting of the American Society of Reproductive Medicine.
Marijuana and Fertility Timing
When it comes to romance, timing is everything. That holds true for fertility, too, says Celia E. Dominguez, MD, of the Center for Reproductive Medicine at Emory University, Atlanta.
“The reason men have millions of sperm is because the fertility process is more difficult than people think,” Dominguez tells WebMD. “The whole process of ascending up the tract to the fallopian tubes and then finding the egg is delicately balanced.”
As the sperm approaches the egg, it receives a signal to start swimming — hard. This hyperactivation lets it push through the egg cover. Pooped out sperm don’t have a chance. Learn about more ways marijuana can affect fertility.
Of course, men who smoke marijuana do get women pregnant. But some men are more fertile than others, or are more fertile at different times of their lives. Smoking marijuana, Burkman warns, will make a borderline-infertile man frankly infertile.
“The marijuana-smoking men had significantly lower semen volume,” Burkman says. “Many had pretty low volume, about half the male norm. If they came to our clinic as patients, we’d tell them they are abnormal. . They are delivering significantly fewer sperm to the female when they have sexual intercourse.”
Burkman’s team studied only men. But she says that when women smoke marijuana, the active ingredient — THC — appears in their reproductive organs and vaginal fluids. Sperm exposed to this THC are likely to act just as sperm exposed to THC in the testes.
“When women smoke marijuana, nicotine, or other drugs, their reproductive fluids contain these drugs,” Burkman says. “The woman smoking marijuana is putting THC into her oviduct, into her cervix. If the man is not smoking but the woman is, his sperm go into her body and hit THC in the vagina, oviduct, and uterus. Her THC is changing his sperm.”
Dominguez says that Burkman’s study is more important than merely warning men and women to avoid marijuana if they want to get pregnant. She says that by learning how the reproductive tracts of men and women respond to different chemical signals, researchers will learn more about how to help people get pregnant — or even to avoid it.
SOURCES: Burkman, L.J. “Marijuana Impacts Sperm function both In Vivo and In Vitro: Semen analyses from Men Smoking Marijuana,” Conference, American Society of Reproductive Medicine, San Antonio, Texas, Oct. 11-15, 2003. Lani J. Burkman, PhD, director, andrology department, University of Buffalo School of Medicine and Biomedical Sciences, Buffalo, N.Y. Celia E. Dominguez, MD, Center for Reproductive Medicine, Emory University, Atlanta.
How Marijuana Can Affect Fertility
Elizabeth Hartney, BSc, MSc, MA, PhD is a psychologist, professor, and Director of the Centre for Health Leadership and Research at Royal Roads University, Canada.
Verywell Mind articles are reviewed by board-certified physicians and mental healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more.
Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.
Although the link between marijuana and fertility is not straightforward—plenty of marijuana smokers get pregnant and get their partners pregnant—some research has demonstrated that marijuana use can negatively impact you, your partner, or the fertility of both of you.
Research suggests that marijuana can negatively affect female fertility in the following ways:
- Decreases libido. Even before intercourse takes place, marijuana use may decreases libido. And if you aren’t feeling in the mood, it’s that much more difficult to get started.
- Increases the risk of miscarriage. Marijuana use also increases the risk of miscarriage. Marijuana is known to cross the placenta and may pose a risk to the fetus, although the effects of marijuana exposure in the womb are not as well documented as the effects of alcohol and some other drugs.
Furthermore, the effects of marijuana on fertility seem to accumulate over time. This means that although teenage girls who smoke marijuana are more likely to get pregnant, by the time a chronic marijuana smoking woman is in her mid-twenties, she may be more likely to experience a delay in getting pregnant.
Despite the relaxation effects that many people associate with marijuana use, research has shown marijuana has negative effects on the male sexual response.
- Increases impotence. Cannabis use has been associated with sexual dysfunction, which can also have negative effects on the male ego. If your partner has been impotent, he may be feeling more pressure to have sex to get you pregnant, but be frustrated with his inability to do so. This can lead to misunderstandings between you that make it more difficult to have sex.
- May lead to premature ejaculation. Marijuana use has been associated with premature ejaculation.
- May decrease sperm count. A regular smoker of marijuana has a risk of having a lower sperm count.
- Affects sperm structure and function. Additionally, the sperm produced by marijuana smoking has been associated with abnormal morphology (shape) and motility (its ability to “swim” and fertilize the egg).
Quit to Prepare for Parenthood
Obviously, if you are both smoking marijuana, you risk increasing the chances of infertility as a couple.
Quitting marijuana can be harder than many long-term marijuana users expect, so you and your partner would be wise to quit as soon as possible, while you still have time to get help before getting pregnant. If either or both parents still use marijuana when the baby arrives, you are increasing the risk that your child may use drugs in the future, and parental drug use is implicated in many difficulties for children and families.
Your family doctor can help you with a referral to a counselor or clinic that can help you both quit. Couples counseling, which is offered by many addiction clinics, would be particularly helpful at this time. If you are already engaged in infertility treatment, coming clean about your marijuana could save you a lot of time, money, and heartache, if marijuana is one of the culprits for your difficulties with conception.
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Bari M, Battista N, Pirazzi V, Maccarrone M. The manifold actions of endocannabinoids on female and male reproductive events. Front Biosci (Landmark Ed). 2011;16:498-516. doi:10.2741/3701