Smoking recreational cannabis is now legal in Canada for adults over 19 years. According to statistics Canada, 27 percent of people aged 15-24 years and 13 percent of people over 25 years of age use cannabis. It is 4.6 million Canadians who are currently consuming products from the cannabis factory, which include marijuana and hashish.
As a fertility doctor, I am aware that men and women in the first reproductive years are also the most common users of marijuana. The drug was already the most popular and fastest growing in North America, and now it's legal, doctors expect marijuana consumption to rise further.
Many couples ask their doctors if marijuana is safe while trying to get pregnant. Unlike alcohol, which we know is dangerous, research on marijuana is not nearly as clear.
Man's sperm can be susceptible to damage from tetrahydrocannabinol (THC), a component of marijuana that causes high effect.
In one study, researchers exposed sperm samples to low, medium and high concentrations of THC. The doses of THC were intended to imitate the recreational and therapeutic use of marijuana. They found a dose-dependent reduction in sperm motility – more THC resulted in slower spermatozoa. Sperm that was of borderline quality was initially most sensitive, showing a 56% reduction in high-dose THC exposure. Even sperm that maintains the ability to swim despite the exposure of THC has significant damage in the ability of the sperm to bind and penetrate the egg.
Watch: The number of sperm counts for men from Western industrial nations. Blog goes below.
These findings are contradictory to previous experiments that did not cause damage to chronic marijuana smoking. However, most of the previous surveys were carried out in the 1970s, using much less sophisticated sperm analysis technology.
It turned out that marijuana disrupts women's ovulation. Laboratory studies in animals and humans have shown that THC is mixed with brain hormones that regulate the ovary and thyroid gland. In some cases, this leads to mature eggs becoming stuck inside the ovaries and never getting rid of the insulin follicles.
Beyond laboratory conditions, the impact of marijuana on fertility is far more difficult to study. Researchers usually rely on research to ask people about their drug use and their plans for children. A recent online survey followed 1125 couples between 2013 and 2017, following their fertility rates and the use of marijuana for self-reporting. The authors conclude that neither male nor female marijuana reduces fertility.
A large US study compares daily marijuana users with those who have never used it. They found no difference between the two groups in terms of the time to think about pregnancy. However, other scientists suggest that cannabis products can be mixed with cannibidal hormones of the body, which are crucial for a growing normal pregnancy.
Andersen Ross through Getty Images Pregnant woman has ultrasound scanning.
Pregnant woman has ultrasound scanning.
It is believed that changes in the female internal cannibinoid system cause serious problems like spontaneous abortion, poor placental growth and abnormal fetal development. In addition, the psychoactive component of marijuana, THC, may pass from the mother's blood to the circulation of the baby and breast milk. The Association of Obstetricians and Gynecologists of Canada has launched a campaign calling on pregnant women and nurses to avoid cannabis.
In short, the research on marijuana so far has shown mixed results. Many laboratory studies have shown harmful effects on sperm, eggs and early pregnancy. However, large studies in humans, full of potential inaccuracy in published data independently, failed to link marijuana to infertility. For now, I advise my patients to avoid the use of cannabis products if they are trying to conceive, are pregnant or breast-feeding.
Sometimes the best advice is the simplest: it's better to be safe than sorry.
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