On the Discovery channel several years ago, there was
a film showing the activity of sperm on their way up the
vaginal canal to fertilize the egg that had been released
from the ovary. Due to the magic of nanotechnology, we
were able to see the whole process of conception in
living color. Thanks to the dramatic music in the
background this film had all the drama and excitement
of the Indianapolis 500.

The egg swole and burst from the ovary. The 200 to 500
million newly released sperm resembled swirling, jumping
schools of minnows in the ocean. Shaped like tiny tadpoles,
darted and jetted, jumping over each other, as if racing away
from a swarm of hungry sharks toward safe harbor. The first
one to reach the egg was quickly surrounded by her and
engulfed. But that was not the woman’s regular partner.

Turns out that that rapid swim, where each sperm was
determined to get there first, is something that happens
when the sperm are introduced to a new partner. (This
explains how one night stands results in a baby.)
When it’s the regular female partner, the sperm are
more laid back – sort of a “We’ll get there when we get
there” in attitude. Now how do you think those sperm
behave when they’re high? Just chillin’ ?

Not enough swimmers

A Tulane University study found low semen volume (only
a small amount of sperm fluid ejaculated) by cannabis
smokers. It is thought that less than 20 million sperm in
a milliliter (about a teaspoon) is a low semen count.

Slow swimmers

Studies have shown that weed had a distinct effect on
sperm. Dr. Daniel Mazur at Urology Associates in
Denver, Colorado participated in research that showed
that men who use marijuana more than once a week have
nearly a 30% reduction in sperm count and sperm
concentration. While these early studies show that
the effects of marijuana last five to six weeks even
after they’ve stopped using it. Heavy marijuana use
lowers sperm counts, decreases sperm motility
(basically, their ability to wriggle toward an egg),
and increases sperm malformation.

Malformed sperm

In a study by a Duke University doctoral student
(at the time), Rose Schrott, there were 177 potential
genetic changes to the gene that is associated with
autism and schizophrenia. Her findings suggest
that there may be a link between the increased
use of cannabis and the increase in cases of
autism. Researchers are currently investigating
links between cannabis use and developmental
problems in offspring of parents who were
chronic users.

What about women’s fertility and
marijuana use?

According to an NIH study, women were about 40%
less likely to conceive per monthly cycle if they had
used marijuana or hashish in the weeks before
pregnancy than women who had not. While that
was a somewhat small study, the ratio of successful
pregnancies to pregnancy losses in cannabis users
was later compared to a larger study of 1200 women
over 6 months of cycles, with similar results. *

Marijuana and changes in women’s hormones

A study at Massachusetts General Hospital showed
that women cannabis users were 2x as likely to experience
pregnancy loss as those who had never used cannabis or
had not used it in the recent past.

It is notable that many of these were first time studies
but areadding to the body of research that indicates
trends. Researchers warn that there is much more
research required for definitive conclusions about
the effects of cannabis on fertility and pregnancy.

*The NIH study can be found here: https://academic.oup.com/humrep/article-lookup/doi/10.1093/humrep/deaa355(link is external)