Strong link between marijuana use during pregnancy, and autism

A major study has revealed a strong link between marijuana use by mothers during pregnancy, and subsequent rates of autism among their children.

A recent analysis of more than 500,000 Canadian mothers and their children revealed a 50% increase in the risk of autism in kids whose mothers had used marijuana while pregnant, according to a report published Monday in Nature Medicine.

. . .

The 503,065 children analyzed — 3,148 of whom had mothers that had used cannabis while pregnant — were followed for an average of seven years. Exactly 7,125 were diagnosed with varying levels of autism.

Researchers found that the rate of autism diagnoses among children with in utero cannabis exposure was 2.2%. Of those whose mothers did not use the drug during pregnancy, only 1.4% were diagnosed with autism.

“Cannabis is not a benign drug and any use during pregnancy should be discouraged,” Corsi said. “We know that cannabinoids can cross placental tissue and enter the fetal bloodstream. There are cannabinoid receptors present in the developing fetus and exposure to cannabis may impact the wiring of the developing brain.”

After researchers accounted for factors that might distort the results, they found that the risk for autism increased by 50% when mothers used cannabis while pregnant.

There’s more at the link.

Needless to say, pro-marijuana voices are already being raised in an attempt to question or discount the results of the survey.  Nevertheless, I remain unsurprised.  I lived in Africa for decades, as regular readers will know.  Marijuana use is endemic there.  I have little doubt that it’s one of the factors affecting the mental development of African children.  The continent rates chronically low on objective measurements of IQ;  and I’m sure drug and alcohol use has more than a little to do with that.  (Yes, mental underdevelopment is not the same as autism, but AFAIK they’re related issues.)

It’s a sobering thought that many of today’s autistic and “special needs” children may have been made that way by their mothers’ self-indulgent behavior.  Lawmakers, too, should take note.  De-criminalizing marijuana use may have had the unintended consequence of condemning many more children to a lifetime of retardation, and possibly permanent incompetence to manage their own lives.



  1. This was known back in the early 1900's. And again in the 1920's, and the 1940's and the 1960's.

    But the pot-users keep pushing a flawed agenda because 'it's natural' and 'it's safer than tobacco.'

    My answer? Cyanide, arsenic, lead are all natural substances. And it's marginally safer if taken orally and digested. Smoked? Poor quality weed is as bad as tobacco. The stronger weeds are much more dangerous and carcinogenic than tobacco.

    Frickin idiots.

  2. The question here is "how much".

    Fetal alcohol evidence is derived from heavy drinkers during pregnancy. It's much less clear whether an occasional glass of wine is harmful. Researchers generally just draw a line — if a lot is really bad, a little will be somewhat bad. Yet real life doesn't work that way — a little of something can be good and a lot bad (fill in most foods and nutrients).

    I'm not defending marijuana use during pregnancy or disputing the study but it helps knowing the relative risk of smoking one joint vs daily use.

  3. All Colorado Marijuana products required mandatory warning label:

    There may be health risks associated with the consumption of this product.
    This product was produced without regulatory oversight for health, safety, or efficacy.
    This marijuana's potency was tested with an allowable + or – 15% variance pursuant to 12-43.4-202(3)(a)(IV)(E),C.R.S.
    There may be additional health risks associated with the consumption of this product for woman who are pregnant, or breastfeeding or planning to becoming pregnant.
    Do not drive or operate heavy machinery while using marijuana.
    The marijuana contained within this package complies with the mandatory contaminant testing by rule R1501.

  4. It seems a big issue is the potency of the marijuana being used and how often. I've never used it and can a piss test, but the marijuana grown now is highly concentrated with THC.

    I don't think people should spend their lives in a stupor, but locking up people for this stuff is not helpful either.

  5. "De-criminalizing marijuana use may have had the unintended consequence of condemning many more children to a lifetime of retardation, and possibly permanent incompetence to manage their own lives"…..


  6. Colorado Marijuana Warning Label:

    Do not drive or operate heavy machinery while using marijuana.

    Let's see… I'm all screwed up. Do I want to play with my gun collection or drive my bulldozer through my dick head of a neighbor's back yard?

    A major study has revealed a strong link between marijuana use by mothers during pregnancy, and subsequent rates of autism among their children.

    And just how the hell do you think they got pregnant in the fist place? As for use during pregnancy, it's simple. What a woman eats, drinks, or imbibes during her pregnancy affects her child's development. That's not a secret and hasn't been for many years.

    The thing about recreational legalized pot is that it gets taxed. If you're going to wrestle the genie back into the bottle, you're going to have to begin with replacing that tax money with something else. Good luck.

  7. So, Mad Jack. Murder, rape, arson, child sex trafficking are all illegal, too, but people still do it, and cause huge amounts of harm. Should we decriminalize them too? (Oh, wait, California basically has decriminalized Child sex trafficking… and rape (if done by illegals or black or hispanics) and murder (if done by illegals.)

    I used to be very libertarian about drugs. But after seeing the collateral damage – destroyed lives of relatives and children who have not taken drugs – I can no longer stand by and say, "Sure, it's your body, go ahead."

    Like, well, that Elephant in the political room, abortion. Yes, I used to agree – her body her choice – when it was supposed to be infrequent and for horrid reasons like rape, incest, incestual rape and so forth, but just for casual kicks? Nope.

    Same with drugs. If the person using the drugs stays home while drugged, has no interaction with anyone while drugged, pays their bills, supports their family, isn't a drain upon society, okay, sure.

    But I have yet to meet even a 'casual marijuana smoker' who isn't a drain upon life and the people around them.

    There is a stigma in society against the over-use of tobacco and booze. There are measures where one can get fired for using either at work or in places, but often the same is not held against drug users – especially marijuana users.


  8. Beans, if you're talking about drugs being illegal from the harm they cause, the real elephant in the room is alcohol. After seeing the collateral damage in destroyed lives, etc related to alcoholics should it remain legal?

    Of course, we tried making alcohol illegal.

    The other question with legalizing drugs is whether it will really increase the number of people using. In terms of stronger and stronger marijuana, prohibition cause more use of distilled spirits (easier to hide per unit of alcohol). Not sure if there have been studies on the relative strength of marijuana products where it's legal.

    And I do know casual marijuana smokers who aren't a drain on life or people.

  9. IMO, all these studies should start with a statement, "We don't know what causes autism. This may be a factor".

    Why? The horrible mental burden on mothers.

    My late ex-wife was devastated when our first born was born autistic. What did she do wrong? At the time Bruno Bettelheim was pushing the theme of "cold mothers". With her second pregnancy, she was even more diligent. Yet, he developed Asperger Syndrome.

    Diligent prenatal care wasn't enough and her mental anguish along with the shear difficulties of raising a near feral child broke her.

    I wonder what the divorce rate is among parents of autistic children?

  10. @Beans @Old NFO
    It's been known that cannabis affects mental developemnt for a long time, but as related to autism. Autism wasn't even identified until the late 30s / early 40s after Kanner and Asperger published their findings independently. So it's not possible that it was known in 1900 or 1920 that maternal cannabis use during pregnancy had any effect on a disorder that hadn't even been identified.

  11. Beans / Thomas W, regarding potheads being a drain:
    I encountered a daily pot smoker a few years ago, at a little mil-tech company. He was productive, but emotionally messed up. Apparently some, if not all, of the messed-uppedness was fallout from a horrible domestic incident some years earlier.
    Anyway, it was no secret that he'd smoke a joint every night, enabling him to sleep and then be productive and mostly functional next day.
    Eventually, the parent company announced a new drug-testing policy, and he had to quit the weed. A couple of months later, he was gone – I don't know if he'd relapsed and failed his test, or if he'd fallen apart from lack of sleep or whatever.
    'Course, this was self-medicating, not recreational use. I'm inclined to agree that recreational users are likely to be unproductive, but how much of that is the pot and how much is the nature of people inclined to use it recreationally is another question.

  12. Beans:

    Right, reason, or none, Colorado legalized marijuana for recreational use. It's sold in stores, and taxed by the State. The reality is that if you (and people like you) want to reverse this situation, step one is replacing all that nice tax money that's going into the State coffers. Again, good luck with that.

    The United States tried prohibition (1920 – 1933) ostensibly for moral reasons – reducing crime, if you can believe it. A lot of people made a ton of money on illegal booze, and prohibition ended. The war on drugs is a dead loser and has been since its inception. Your other example, abortion, was legal until the late 1800s – and the rest is history.

    Making new laws doesn't work, but that's what the government continues to do.

  13. WSF:

    autism is an inheritable genetic condition. It is the far end of the ADD/ADHD-Aspergers-autism spectrum.

    It appears that concentrating the genes of parents with ADD tends to produce kids with ADD and/or Aspergers Syndrome. Further mating of their offspring with similar types can produce Aspergers or autism.

    Want to limit the creation of autism? Identify everyone who has ADD or Aspergers and inform them that they must avoid relationships with similar people. One problem I see is that ADD and Aspergers is not as visible in females as it is in males. However, they ARE attracted to each other. Like attracts like when humans have a choice.

  14. BTW, since it began, Silicon Valley has been fueled by marijuana, especially the software end of it. The interaction of this drug use and the high concentration of ADD and Aspergers in this area may have had some sort of synergistic effect on creativity, perhaps. I can't say one way or the other, but have seen them be company founders. One I know of personally has two startups to his name. And those two occurred AFTER he retired the first time.

  15. As a Journeyman Mechanic, here are my observations regarding marijuana.
    Those that "light up" every day after work and have three or more joints in the process have proved to me they are not worth having as employees – this even in comparison to others who will consume three beer every day after work.
    There is usually a tipping point where the mechanic's diagnostic abilities either level off or decline – normally when they reach their mid twenties. Any progress afterward is not truly considered advancement of the learning process, rather experience has taught them to simply replace parts following a known solution. The vast majority of those who are faced with new conditions and are pressured to provide a solution will almost universally become upset and proceed to continuously throw parts at a machine until it finally runs.
    As well, far too many of these 'mechanics' habitually fail to complete the basics of diagnostics, particularly no fuel or insufficient battery power for proper functions.

    In short, chronic use of marijuana is worse than similar use of alcohol. It has proven to me it impedes process thinking and problem solving.

    Regardless of what the drug dealers and 'focused studies' will say (and according to them, pot fixes everything except bad breath), they are misleading to the point of outright lying.

    On the bright side, I do fix many, many of their failures. And I charge heavily for it.

  16. As someone who is on the autism spectrum myself (high-functioning end) I do have some opinions on this topic.
    For the last 80 years, people have blamed autism on all kinds of things, mostly environmental. The truth is, it is primarily genetic. The CDC's website has a section on autism; they say it is now known to be 70-80% genetic. There is an Italian study I have heard of, but not actually seen, that came out at 95%. The "epidemic" is mostly that the medical/psychology establishment is getting slightly better at spotting it, at least in children. Nobody really knows how many there are in the US, let alone the world. The conservative estimate is that there may be as many autistics in the US as there are Jews; the far-out one is that we are 15% of the population.
    As far as eliminating it by policing who mates with who: besides being a totalitarian approach, it would probably be suicidal for the human race–a lot of human creativity would be lost, both in the arts and sciences. Among those strongly suspected of being autistic, based on their known behaviors, were Isaac Newton, Albert Einstein, Nikola Tesla, Lewis Carrol, Michelangelo, Mozart and more.

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