Recent research has looked at the relationship between marijuana use and fertility.

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Using marijuana on a regular basis may affect fertility for both men and women. Getty Images

As recreational marijuana is legalized in more and more places, marijuana use is likely to go up — especially among people of reproductive age.

Consequently, it’s important to understand marijuana’s effect on fertility so doctors can properly counsel people who are trying to get pregnant.

Most people already know that smoking marijuana is harmful for sperm health but researchers wanted to know how accurate that adage was and if the effects extended to women’s reproductive health as well.

In an effort to better inform healthcare providers about what we do and don’t know about marijuana’s effect on fertility, researchers outlined five things to know about the relationship between the drug and one’s ability to conceive in a new article published in the Canadian Medical Association Journaltoday.

“The most concerning thing is that even though marijuana has the potential to significantly affect the reproductive system there is very little evidence on the actual clinical effects. For this reason anyone trying to conceive should avoid marijuana,” Dr. Sara Ilnitsky, study co-author and reproductive endocrinology and infertility fellow at Western University in London, Ontario, told Healthline.

The endocannabinoid system is a complex network of receptors throughout our bodies that help regulate and communicate with the brain, endocrine tissues, and immune system.

This system is especially prevalent in the reproductive organs of both sexes and plays a critical role in controlling hormones and human reproduction, according to Dr. Kecia Gaither, an OB-GYN and maternal fetal medicine physician at NYC Health + Hospitals/Lincoln in the Bronx, New York.

The active, psychoactive ingredient in marijuana — tetrahydrocannabinol (THC) — acts on the endocannabinoid receptors, causing a wide array of biological effects.

“THC, one of the major components of marijuana, interferes with the functioning of this communication process,” says Gaither.

Consequently, THC can interrupt many of our body’s reproductive functions and throw them off balance.

The paper also pointed out that marijuana use can cause sperm counts to take a major hit.

A 2015 study found that men who regularly smoked marijuana saw a 29 percent drop in their sperm counts.

Interestingly, another recent paper on human reproduction showed higher sperm counts in men who had ever used marijuana when compared to men who never used marijuana.

Regardless, more research is needed to better understand the short and long-term impact marijuana has on sperm health.

“This discrepancy in findings demonstrates that there’s a clear need for more research in this area,” Ilnitsky said in a podcast supplementing the practice article.

According to Ilnitsky, it’s much harder to study marijuana’s effect on women’s fertility because we don’t have a direct measure to look at, as we do with semen in men.

That said, one study discovered that smoking marijuana can delay the ovulation cycle by a few days.

“High amounts of THC can decrease the production of estrogen and without the high estrogen spike, ovulation will not occur,” Dr. Felice Gersh, an OB-GYN and founder of the Integrative Medical Group in Irvine, California, told Healthline.

If ovulation doesn’t occur, no egg will be released and there will be no chance an egg will be fertilized.

Considering the effects marijuana can have on fertility — namely reduced sperm motility and delayed ovulation — it appears that marijuana could potentially exasperate any difficulties a couple may have getting pregnant.

“Marijuana interferes with the normal functioning of our endocannabinoid system, and that complex biological system is involved with every aspect of fertility-ovulation, tubal transport, readying of the uterine lining, and timing and proper implantation of the embryo at the blastocyst stage,” Gersh said.

“Consequently, marijuana can potentially take any fertility problem and make it worse, simply by impacting all of these aspects of the reproductive system,” Gersh added.

That said, previous evidence suggests that couples without fertility issues will not experience major issues conceiving if they use marijuana somewhat regularly.

All things considered, health experts agree that we definitely need more research on marijuana’s health effects.

“Given the climate of legalization of marijuana, I do foresee a likely increase in research addressing not only the effects on fertility — but also pregnancy outcome from fetuses exposed in utero to the effects of cannabis on their structural, neurological, and intellectual functioning,” Gaither said.

Experts hope to also understand what happens when you stop using marijuana along with the drug’s potential benefits.

“Research is needed to see if perhaps there can be any as yet unrecognized benefits for select couples. Perhaps it can improve sleep and lower stress in small amounts and improved fertility for some,” Gersh said.

The biggest challenge researchers currently face is that it can be difficult to quantify the amount or concentration of THC people are exposed to, according to Ilnitsky.

Self-reported data can be largely inaccurate, especially with large population-based studies.

In the meantime, if you’re planning to conceive, Ilnitsky recommends cleaning up your lifestyle — eat healthier, exercise regularly, and restrain from drinking and smoking.

When it comes to marijuana use, it’s best to err on the side of caution.

“My advice would be to just avoid it if possible,” Ilnitsky said in the podcast.

Lastly, if you use marijuana for therapeutic purposes, it’s crucial to weigh the risks and benefits. Talk to your healthcare provider and try to determine whether or not the risks are worth taking before and during your pregnancy.

As marijuana becomes legalized in more places, marijuana use will continue to increase. In order to understand marijuana’s effect on fertility and help doctors better counsel their patients, researchers published five things to know about the drug’s impact on fertility.

In general, for people trying to get pregnant, it’s best to avoid marijuana.