Cannabis Science

Can Smoking Weed Affect Getting Pregnant?

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Marijuana has been used for thousands of years. People used marijuana to get high as well as treat various ailments. However, the science behind it wasn’t understood. Now, with more research, scientists have a better idea of how weed affects our bodies. While more research is needed, there are several studies popping up about weed and fertility. Can smoking weed affect getting pregnant? Here’s what we know. 

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Can Weed Affect Fertility?

It’s understood that weed should be avoided during pregnancy but what about before? Well, there are a couple of studies that show that weed can affect the fertility of either party.

Felice Gersh, MD, OB/GYN, founder/director of the Integrative Medical Group of Irvine told WebMD that marijuana can affect fertility. Gersh says weed can lower the potential to conceive. The reason that may be true is due to the relationship between the endocannabinoid system and the reproductive system. 

Gersh said, “The sex hormones and our own endocannabinoids up and down-regulate each other throughout the menstrual cycle to facilitate reproductive success. Anything interfering with that complex feedback system will negatively impact fertility.”

According to an article in the Canadian Medical Association Journal (CMAJ), the endogenous endocannabinoid system is also found in the reproductive systems. Therefore, weed can impact the organs in these systems.

However, for the majority of couples, weed probably won’t cause fertility problems. As a matter of fact, a 2018 study examined the time to pregnancy for stoners. To be clear, time to pregnancy is defined as “the number of months of unprotected intercourse that elapse before conception occurs.” 

The study concluded, “suggests that neither marijuana use nor the frequency of marijuana use was associated with time to pregnancy for men and women.”

On the other hand, a 2021 study said women who had used cannabis while trying to conceive were 41% less likely to conceive than non-users. 

As a matter of fact, the CMAJ article said that weed could harm the fertility efforts of couples struggling to get pregnant. It said, “….for couples with infertility, the changes in ovulatory function and sperm count associated with smoking marijuana could compound their difficulty with conceiving.”

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Ways Smoking Weed Can Affect Getting Pregnant

There are a couple of studies and articles that show the various ways that smoking weed can affect getting pregnant. Some key ways marijuana can affect getting pregnant are lowering sperm count and delaying ovulation. As a disclaimer, there are not many studies surrounding weed and fertility and the studies are small. In addition to that, there could be other reasons why the participants were having lower sperm count or delayed ovulation other than weed. However, it’s important to explore the possible correlation between the two. 

Lower Sperm Count 

Some studies have shown that stoners have lower sperm count. Having a lower sperm count decreases the chance of fertilizing an egg. However, it does not eliminate it. Therefore, if you have a low sperm count, you can still have kids. 

A 2015 study showed that people who smoked more than once per week were associated with a 28% lower sperm concentration and a 29% lower total sperm count after adjustment for confounders. In addition to that, weekly cannabis use along with other recreational drugs reduced the sperm concentration by 52% and the total sperm count by 55%.

The study said they can’t exclude the possibility of other things affecting fertility such as lifestyle. The study said, “We cannot exclude the possibility that the men who used marijuana generally have an unhealthier lifestyle and health behavior, which may also affect their semen quality and hormone levels.” However, the study adjusted for known lifestyle factors. 

Another study says that men who have never smoked marijuana had significantly higher sperm

concentration than men who had never smoked marijuana. The study also mentioned, “longer duration since last use of marijuana was related to higher sperm count.”

Delay or Inhibit Ovulation

Ovulation is paramount for traditional pregnancy. Unfortunately, a study found that weed may delay or inhibit ovulation completely. This specific study, conducted in 2007, examined 201 women. The study found, “Occasional marijuana users (up to three times in the last 3 months) had a longer follicular phase than nonusers (3.5 days). The follicular phase in frequent users (more than three times) was almost 2 days longer than that of nonusers.”

You may be wondering about the significance of late ovulation. Well, according to Flo, late ovulation decreases the chance of pregnancy. 

In addition to that, 43% of the women in the study had inhibited ovulation. THC can interfere with estrogen production and therefore inhibit ovulation. Dr. Felice Gersh, an OB-GYN told Healthline, “High amounts of THC can decrease the production of estrogen and without the high estrogen spike, ovulation will not occur,”

Can Smoking Weed Help You Get Pregnant?

There are no studies, (that we know of at least), that show that weed can help fertility. However, that doesn’t mean that weed can’t technically help people get pregnant. 

Our premise has to do with weed and its relationship with sex. For some stoners, weed makes sex more enjoyable. In addition to that, for some people, weed increases their sex drive. Therefore, if people are having more sex, there is a higher chance they’ll get pregnant. 

Of course, this isn’t everyone’s experience. Some stoners report erectile dysfunction after using weed which can definitely put a hamper on conception. In addition to that, weed may decrease libido in some users which may affect their willingness to have sex and ultimately prevent conception. 

It should also be stated that if you’re having fertility problems, please see a doctor as soon as you can. 


Can smoking weed affect getting pregnant? Yes. First of all, there needs to be way more research done around weed and fertility. At the same time, some studies show that weed may cause some problems with fertility. However, these studies are small and there could be other reasons why the participants were having problems. Still, if you are having problems conceiving, see a doctor so you can get to the bottom of the issue. Finally, we do know that weed can affect the reproductive system so we’re looking forward to more research.


About Trevann

Trevann is Stoner Rotation’s Jamaica-based lead writer for the Science section of our cannabis blog. She graduated with honors receiving her Bachelor of Science degree in Molecular Biology from the University of West Indies, Mona. For the last three years, she has covered some of the biggest questions around cannabis and health underpinned with research from supporting studies, medical journals and scholarly articles. Got something on your mind? You can reach her at [email protected].