Researchers say pot can affect fertility

LONDON, ONT. A pair of London researchers are trying to set the record straight on what would-be parents should know about pot.

Western University researchers are spreading the word about how marijuana may affect fertility, rounding up 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 healthcare providers’ knowledge and relates to the lack of available evidence,” said Dr. 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.

In the paper, Ilnitsky and her colleague Stan Van Uum, an assistant professor in clinical pharmacology and endocrinology at Western, said tetrahydrocannabinol (THC) — the psychoactive ingredient in pot — acts on receptors in the pituitary gland and reproductive organs in both men and women.

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

The researchers also say pot may delay or prevent ovulation and can decrease sperm count.

Smoking marijuana more than once a week is associated with a 29-per-cent drop in sperm count, the researchers say.

Sperm mobility and form were unaffected.

An American study found smoking marijuana — from less than once a month to daily — in either partner did not significantly affect the time it took to conceive. The Western researchers say for couples already coping with infertility issues, pot may compound the difficulty in getting pregnant.

The message is even more pressing since recreational marijuana became legal in Canada last fall and Ontario’s first legal pot stores opened in April.

“Legalization will likely increase marijuana use among reproductive-aged men and women, so we wanted to help inform health-care providers of what we do and do not know about marijuana’s effect on fertility,” Ilnitsky said in a statement.

Both Ilnitsky and Van Uum want the article and podcast to spark a conversation about pot usage and fertility and prompt other researchers to take on more rigorous scientific studies.