Cannabis legalization means more and more people are able to take marijuana medicinally and recreationally. But as cannabis consumption increases, many are wondering what affect marijuana may have on our reproductive health. From lowering sperm count and testosterone levels in men to causing skipped periods or creating an inhospitable environment for sperm in women, there are potential impacts that cannabis can have on your ability to get pregnant.
Does cannabis use lead to infertility? Should you stop consuming cannabis if you’re trying to conceive?
For those folks who are trying for a baby, these questions—and their answers—are crucial. And the data may surprise you.
It’s no secret that cannabis seems to affect fertility in men. But how and to what extent? If you’re a man who uses cannabis and are trying to conceive, it’s important to get the facts straight. Here are a few of the cannabis fertility factors that we know about for men.
Rumors of the plant causing lower sperm count have been floating around for a while now. And researchers are compiling some pretty significant evidence to back up these claims.
In 2003, researchers from the University of Buffalo found that when compared with healthy fertile controls, men who used cannabis daily had lower sperm count and less semen volume. More recently, a [2015 study from the American Journal of Epidemiology supported these findings with similar results. They found that men who consumed cannabis more than once a week had on average a 29% lower sperm count and 28% lower sperm concentration than men who didn't consume cannabis.
This all suggests that cannabis can drastically affect sperm count when consumed regularly. So, if you’re trying to conceive and having a hard time, marijuana could be the culprit.
But don’t start thinking of cannabis as a form of male birth control. It’s still very possible to get someone pregnant while using cannabis. Lani J. Burkman, Ph.D., the researcher who led the 2003 study, says not all men who use cannabis suffer from infertility.
She explains, "The men who are most affected likely have naturally occurring borderline fertility potential, and THC (tetrahydrocannabinol) from marijuana may push them over the edge into infertility."
Still, most men who have borderline fertility potential don’t know it, and overall sperm counts have been dropping in the Western world over the last 40 years. As sperm counts fall for other reasons, understanding the effects from cannabis may become increasingly more important for those who want to have kids.
The good news is that a decline in sperm count seems to reverse after a period of marijuana abstinence. So, if you’re worried about your cannabis consumption negatively affecting your sperm count, take a little break from marijuana.
Interestingly, Burkman also found in her research that the sperm of cannabis-using men were affected by something called “hyperactivation.” These sperm acted differently than the sperm of most men who didn’t consume cannabis.
Usually, after ejaculation, the sperm will remain in a resting state, moving with the semen rather than swimming themselves. Then, at a certain point, the sperm kick into gear and start swimming to get to the egg.
Hyperactivated sperm start swimming early. They start swimming too quickly and so may tire themselves out before the period when their swimming is most crucial. While we need more research to fully understand the implications of this finding, it helps explain why some may have trouble conceiving while consuming cannabis.
Another worry is that cannabis can cause reduced testosterone in men. Animal studies have shown this can happen in male mice, rats and monkeys. In these studies, researchers found lowered testosterone rates in animals that were chronically exposed to cannabis. Researchers also found reduced prostate and seminal vesicle weights as well as altered testicular function.
Researchers have also found decreases of testosterone in human males using cannabis. But research in humans has been limited, and studies sometime conflict or contradict each other. While some support the idea that cannabis use lowers testosterone, others find that testosterone changes we’ve seen in the research aren’t statistically significant.
One ray of hope is that testosterone loss doesn’t seem to be permanent. In animal studies, subjects continually exposed to marijuana seemed to develop a tolerance to the effect of the plant on testosterone levels. Plus, stopping cannabis exposure altogether seemed to restore testosterone to normal levels.
While the conversation around cannabis-related infertility often seems to focus on men, there are also fertility concerns for women. Here are few of the issues women should consider when evaluating whether they should put cannabis to the side while trying to get pregnant.
As with testosterone in men, there are worries that cannabis may mess with a woman's hormonal cycle. In fact, some research shows that cannabis can increase the likelihood of skipped or delayed ovulation, and even cause problems with embryo implantation. A study in 1990 showed slight increases in ovulatory abnormalities for cannabis-consuming women. That said, the study couldn’t demonstrate consistency in the effects. In fact, the only group that seemed effected was the group that consumed cannabis with low frequency.
This makes sense with animal studies, which show that primates can develop a tolerance to the cycle-disrupting effects of cannabis. [While primates given THC regularly experience an initial disruption to their ovulation cycles, after being exposed for some time, they become THC-tolerant, and their cycles go back to their previous state.
In other words, starting a regimen of cannabis use right before you try to get pregnant could lead to some problems. But if you’re a long-term medical marijuana consumer, you’re likely to experience disrupted menstrual cycles.
Women who use cannabis should also understand the effect it may have on sperm trying to enter their reproductive system. Increased levels of THC may create an environment that hinders sperm from making their journey into the egg. Studies show that sperm exposed to THC are less able to release a special enzyme that they use to travel through the egg’s cell wall and into the egg.
Another risk factor for women who consume cannabis while trying to get pregnant is what happens if they succeed and continue using cannabis before discovering they’re pregnant. While more research needs to be done, there are some concerns about cannabis use during pregnancy.
Some point to a study, which concluded that THC crosses into the placenta and affects the fetus’s developing brain. Others point to a different study performed in the 1980s in Jamaica; this one suggested cannabis exposure had no effect on children’s cognitive functioning. HelloMD’s Chief Medical Officer Dr. Perry Solomon recommends that women who believe they may be pregnant stop cannabis use immediately to avoid any complications.
With all of the bad press about cannabis leading to infertility, and the research showing the many fertility factors it can affect, you’d think we could say with confidence that cannabis leads to lower fertility. But the research isn’t that clear.
In fact, research looking at whether cannabis-consuming couples end up conceiving shows no connection between cannabis use and pregnancy. A recent study looked at couples trying to get pregnant, and found that cannabis consumers were just as successful in conceiving as their non-cannabis consuming counterparts. Perhaps cannabis is boosting another fertility factor we don’t know about and making up for the fertility problems described above?
That’s just one theory. But we need more research to get the full picture on how cannabis interacts with fertility. In the meantime, consulting with a qualified doctor who has experience with cannabis is the best way to learn about how to navigate the questions about cannabis and fertility. Don’t have a cannabis doctor near you? You can consult with HelloMD’s knowledgeable doctors online from the comfort of your home.
Photo credit: Christiana Rivers