Western University researchers are trying to set the record straight about how marijuana may affect fertility, rounding up the latest research findings in a podcast episode and article for the Canadian Medical Association Journal.

“The general public’s knowledge about the effects of marijuana on fertility is limited.

This is equally true of health care providers’ knowledge,” said Sara Ilnitsky, a reproductive endocrinology and infertility fellow at Western’s Schulich school of medicine and dentistry.

She also practises at London Health Sciences Centre’s fertility clinic.

While there are some studies on the relationship between fertility and marijuana use, the number of studies and the quality of the research often leaves something to be desired, Ilnitsky said.

Ilnitsky and her colleague Stan Van Uum, an assistant professor in clinical pharmacology and endocrinology at Western, want the article and podcast to spark a conversation about pot use and fertility and prompt other researchers to take on more rigourous scientific studies on the topic.

“Since marijuana is not legal in the majority of places, there has been a hesitancy to admit to using it, or to even ask people about it,” Ilnitsky said.

“The hope is that this might prompt people to become interested in the topic and do some of their own good quality research.”

In the review of existing research studies, Ilnitsky and Van Uum said tetrahydrocannabinol (THC) – the psychoactive ingredient in cannabis – acts on receptors in the pituitary gland and reproductive organs in both men and women.

The pituitary gland, located at the base of the brain, produces hormones but also acts as master gland, stimulating other glandular tissue in the body to produce hormones of their own.

“There are receptors for cannabis-like molecules in the brain,” Ilnitsky said. “There are also cannabinoid receptors in the testes and ovaries. . . . There are many levels where it can be having an effect.”

The researchers also say pot may delay or prevent ovulation and can decrease sperm count. One study in the review found smoking marijuana more than once a week was associated with a 29 per cent drop in sperm count. Sperm mobility and form were not affected.

Another study in the United States found smoking marijuana, ranging from less than once a month to daily, in either partner did not significantly affect the time it took to conceive. But the Western researchers warn the sperm count and potential hormonal side effects of pot may make things harder for couples already coping with infertility.

“These are the people we’re a bit more worried about, because if you knock down the sperm count a little bit and you mess with ovulation a little bit, those could compound things that already are going on in the background,” Ilnitsky said.

Raising awareness of the potential fertility impacts of pot is even more pressing since recreational marijuana became legal in Canada last fall and Ontario’s first legal pot stores opened in April.

Ilnitsky would like to launch a large-scale study of her own on fertility and marijuana use in the future.