Smoking Marijuana Lowers Fertility
Sperm Burn Out, Less Potent When Men — or Women — Smoke Marijuana
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.В 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.
Marijuana smoking makes sperm less fertile — even if the woman is the one who smokes it, a new study suggests.
How Marijuana Can Affect Fertility
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.
Learn about whether marijuana can cause infertility, including a review of research on marijuana's effects on women and men.