Canada was the second country in the world to legalize marijuana (Uruguay was the first). The legalizing act calls it “cannabis” of course. So much more genteel than marijuana, eh? “Cannabis” sounds scientific, well-researched – while marijuana sounds kind of louche and stoned, too close to low-rent, pejorative sobriquets like pot, weed, hash, grass, ganja, reefer et al. 

But it’s still marijuana, and I still call it that, because the people who worked hardest to get it legalized did their best to bypass or suppress the actual scientific research that would have slowed legalization down or even stopped it. 

Since legalization last October, usage has increased, as one might expect. In the first quarter of 2019, there were 646,000 new users, mostly male, mostly over age 45. Many of the new users are doubtless assuming that the government scrupulously and objectively investigated marijuana’s effects on human health, and that they can be confident no harms will come to them with moderate usage. 

That is not the case. Unlike other substances like tobacco and alcohol, where complete transparency on scientific consensus has created hyper-awareness of their inherent perils in the population, marijuana is a substance so swathed in stakeholder propaganda and ideology that the average Canadian, bombarded by claims of pot’s harmlessness and/or therapeutic value, is steeped in ignorance of marijuana’s epidemiologically tracked physical and mental risks.

The medical literature on marijuana has been expanding exponentially over the last 30 years. For an overview of what credible longitudinal research is telling us, I recommend the new book by former New York Times reporter Alex Berenson: Tell Your Children: The truth about marijuana, mental illness and violence

My focus today is the use of marijuana during pregnancy (and even in the weeks before becoming pregnant). For one of the highly-touted benefits of marijuana is its ability to reduce nausea. It is true that many cancer patients attest to its value in quelling chemo-related nausea. But that does not mean that marijuana is safe for all forms of nausea. Yet unfortunately, many pregnant women who suffer extreme morning sickness are following their example, as though it were completely safe for them as well. Health Canada warns against smoking while pregnant, but clearly more on the general principle of better-safe-than-sorry, and more important, the warning is only issued passively. You need to look for it on their site. 

There has been no national educational campaign to warn pregnant women not to use marijuana, nor have women contemplating pregnancy been made aware in any systematic way that marijuana is fat-soluble and can be stored in human tissue for many weeks. Small wonder researchers at the University of British Columbia found that up to one-third of pregnant women believe it is safe to ingest cannabis during pregnancy. It doesn’t help when a major cable outlet like NBC, in a segment on pregnant mothers who smoke marijuana, skews positive, with scant pushback on its deficits, and actually steers viewers to a (Canada-based) support group for mothers who use marijuana. 

The mainstream Canadian media has not on the whole shown much interest in exploring the issue in depth. A September 2018 article in Macleans describes the research on pregnancy-related marijuana use as “largely inconclusive.” Actually, quite a bit of research has been done in this area and much of it is conclusive enough to be taken seriously, but it does not get a great deal of attention, because it is, so to speak, cannaboidly incorrect. 

For example, one study published just this past May in the Journal of Obstetrics and Gynecology Canada, which looked at data surrounding over twelve million pregnancies informs us that the incidence of cannabis abuse or dependence rose from 3.22 in 1000 births in 1999 to 8.55 in 1000 births in 2013. The report concludes that women reporting cannabis dependence or abuse were more likely to have a preterm premature rupture of membranes, a hospital stay of more than seven days, and an intrauterine fetal demise. As well, neonates born to marijuana-exposed mothers had a higher risk of prematurity. 

Up to a five-fold risk of premature birth with marijuana usage during pregnancy is backed up by this study from Australia. “Our results suggest that more than 6% of pre-term births could have been prevented if women did not use marijuana during pregnancy, irrespective of other risk factors,” says lead author Professor Claire Roberts from the [University of Adelaide’s] Robinson Research Institute.

A meta-analysis by the U.S. National Library of Medicine National Institute of Health of 24 studies on the link between neo-natal deficits and marijuana published the following results: Women who used marijuana during pregnancy had an increase in the odds of anemia compared with pregnant women who didn’t use. Infants exposed to marijuana in utero had a decrease in birth weight compared with infants who weren’t exposed. Infants exposed to marijuana in utero were also more likely to need placement in the neonatal intensive care unit.

Daniel Hardy, a professor at the Schulich School of Medicine and Dentistry, had observed with some concern anecdotal evidence from his obstetrical colleagues that a number of their pregnant patients were self-medicating with marijuana against nausea. He led a study that will soon be published inquiring into the impact of THC exposure in utero. Previous studies have found a correlation with marijuana use in pregnancy and lower birth weight, as well as a body of evidence linking marijuana use in pregnancy with children suffering from anxiety and social disorders, he says. “But no one had looked at metabolic outcomes.” 

Hardy’s team did controlled animal experiments. Their conclusion: “Marijuana—THC—binds to two cannabinoid receptors and most people think these receptors are only in your brain, so the effects of cannabis are only in the brain. But we have those receptors in our metabolic organs—in the developing heart, developing adipose (fat) tissue, the pancreas. It made sense to look, long-term whether THC in pregnancy, during a critical window of development of these organs, affects not only the organ weights, but long-term metabolic function. The results are astounding to date.”

Please note: Two of the three studies mentioned above were published after marijuana was legalized. I think it is fair to say that in the rush to impress his progressive voter base with his enlightened views on a subject dear to their heart, Justin Trudeau was more interested in his hipster legacy than marijuana’s fine scientific details. I daresay his government will, if re-elected, and for as long as it can, continue to ignore a growing body of evidence proving that marijuana poses an elevated risk for the offspring of marijuana-using pregnant and even pre-pregnant women. 

It will be harder for his government to disregard the more publicized, irrefutably established risks for psychosis in marijuana users up to the age of 25 when the brain is finally fully formed. (The term “reefer madness” is almost invariably employed as a term of ridicule for people who think like me on this subject—and in fact was used in precisely that way by my editorial board at the National Post in 2008 when I warned of the psychosis danger in a column—but won’t be eventually when even marijuana advocates are forced to recognize certain epidemiological truths). 

Hardy asks, “Why did they start with legalizing marijuana for all ages and all groups? We need to proactively say this is not a good idea for pregnant women to use this drug. And the message needs to come from Health Canada.” Since it isn’t coming from them so far, please pass the message along to anyone you know who is pregnant or considering becoming pregnant.