CBD and THC use during early pregnancy can disrupt fetal development

Summary: Brain and fetal development damage caused by exposure to CBD and THC are very similar defects seen in fetal alcohol syndrome.

Source: University of North Carolina Health Care

A new study published in Scientific Reports, a Nature Research journal, shows how a one-time exposure during early pregnancy to cannabinoids (CBs) – both synthetic and natural – can cause growth issues in a developing embryo. This is the first research to show such a connection in mammals.

The study was performed in mice, which are very accurate models for the development that occurs during early pregnancy, according to the study’s senior author, Scott Parnell, PhD, assistant professor of cell biology and physiology in the UNC School of Medicine.

“The development of the embryo in this time period is very similar across all vertebrates,” said Parnell, a member of the UNC Bowles Center for Alcohol Studies. “In this study we also test a synthetic cannabinoid in zebrafish that yielded similar growth deformations as the natural CBs. Having the same results across animal models reinforces our findings.”

In this study, the brain and facial developmental effects caused by one-time exposure to CBs – CBD and THC (the primary ingredients of marijuana) – are very similar to what is seen in fetal alcohol syndrome (FAS). Parnell and colleagues also found that when CBs and alcohol were used together, the likelihood of these birth defects more than doubled. They went on to show that these drugs may be causing defects by interacting on a basic cellular level and disrupting signaling between molecules and cells that control growth and development.

“The interaction between alcohol and CBs we witnessed is very concerning,” said the study’s first author, Eric Fish, PhD, research associate in the UNC School of Medicine Bowles Center for Alcohol Studies. “Previous studies have shown that CBs and alcohol are frequently used together, and for pregnant women we’re learning that could be very dangerous to a developing child.”

This shows fetal brain scans
Images are stained sections of fetal mouse brains. (Left) The brain of a control mouse. (Right) The brain of a mouse exposed to alcohol and a cannabinoid on the 8th day of pregnancy. Note the enlarged cerebral ventricle caused by the loss of the midline septal region (black arrow). The image is credited to UNC School of Medicine.

In the study CBs, and CBs with alcohol, were given in varying amounts on day eight of pregnancy, which is comparable to the third and fourth weeks of pregnancy in humans. This time period is when alcohol and CB exposure is especially damaging to a developing embryo, and is before some women know they are pregnant. The CBD amounts administered were within what is considered a therapeutic range for humans. The THC concentration administered was similar to levels reached by a person smoking marijuana.

“It is concerning how little we know about the use of marijuana, its CBs, and products like CBD oil during pregnancy,” Parnell said. “We know that there is no safe period to drink alcohol during a pregnancy, and I think this research shows the same is likely true of marijuana use.”

With the results of these one-time exposures, Parnell and Fish are planning to now test smaller, multiple exposures throughout a pregnancy that better mimics real-life usage in human pregnancy.

Funding: This research was supported by grants U01-AA021651 and U54-AA019765 from the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health. This work was done, in part, with the Collaborative Initiative on Fetal Alcohol Spectrum Disorders (CIFASD), which is funded by grants from NIAAA.

About this neuroscience research article

University of North Carolina Health Care
Media Contacts:
Carleigh Gabryel – University of North Carolina Health Care
Image Source:
The image is credited to UNC School of Medicine.

Original Research: Open access
“Cannabinoids Exacerbate Alcohol Teratogenesis by a CB1-Hedgehog Interaction”. Eric W. Fish, Laura B. Murdaugh, Chengjin Zhang, Karen E. Boschen, Oswald Boa-Amponsem, Haley N. Mendoza-Romero, Michael Tarpley, Lhoucine Chdid, Somnath Mukhopadhyay, Gregory J. Cole, Kevin P. Williams & Scott E. Parnell.
Scientific Reports doi:10.1038/s41598-019-52336-w.


Cannabinoids Exacerbate Alcohol Teratogenesis by a CB1-Hedgehog Interaction

We tested whether cannabinoids (CBs) potentiate alcohol-induced birth defects in mice and zebrafish, and explored the underlying pathogenic mechanisms on Sonic Hedgehog (Shh) signaling. The CBs, Δ9-THC, cannabidiol, HU-210, and CP 55,940 caused alcohol-like effects on craniofacial and brain development, phenocopying Shh mutations. Combined exposure to even low doses of alcohol with THC, HU-210, or CP 55,940 caused a greater incidence of birth defects, particularly of the eyes, than did either treatment alone. Consistent with the hypothesis that these defects are caused by deficient Shh, we found that CBs reduced Shh signaling by inhibiting Smoothened (Smo), while Shh mRNA or a CB1 receptor antagonist attenuated CB-induced birth defects. Proximity ligation experiments identified novel CB1-Smo heteromers, suggesting allosteric CB1-Smo interactions. In addition to raising concerns about the safety of cannabinoid and alcohol exposure during early embryonic development, this study establishes a novel link between two distinct signaling pathways and has widespread implications for development, as well as diseases such as addiction and cancer.

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  1. “This is the first research to show such a connection in mammals.” Meaning: It’s inconclusive results. More research involving actual humans and actual cannabis derived cannabinoids needs to be done before making the statements in this research. Mice aren’t humans, as we’ve found out in mass drug recalls.

  2. I agree with all the comments above, I wonder on the angle on this study? is it to scare people about CBD or is it to really help educate consumers or advising them to be cautious. Either which way, what dosage has been tried? how did they arrive at a Therapeutic dosage standard for Humans? THC levels compared to the same what a person would smoke? really? This is so confusing and conflicting. In pursuit to come with some kind of new study and create a new wave of confusion, the easiest bait is using it on Mice. There was another similar research done for Anxiety and CBD benefits and I believe to escalate a normal Mice anxiety levels, they tried placing a brazillian snake in front of it before testing efficacy of these products. Its shameful and disgusting to keep using these kind of baits.

  3. BS. Im glad they put who funded them. The article is vague and shows the brain of the mouse that was exposed to both alcohol and cannabis and try to say the cannabis caused the problem. There’s an old study allegedly on marijuana and pregnancy where they did the same thing. The subjects used alcohol too and they claimed the babies suffered fetal alcohol-like symptoms from the marijuana. No way it was caused by the alcohol, right? There’s a study from Jamaica proving marijuana is safe during pregnancy. The babies even became more alert and responsive to their environments quicker than babies that weren’t exposed to marijuana in the womb.

  4. This is BS. Scare Tactics. Of course alcohol is detrimental but this study is with cannabis and alcohol. Cannabis cannot hurt your brain, if anything, it helps connect the firing responses in it. Also, we aren’t mice or fish or whatever else animals were tested. Cannabis is actually part of human DNA. Look it up people, before believing this RIDICULOUS nonsense. Having 5 children of my own and using cannabis early in pregnancy for morning sickness, none of them have any medical issues and were and are smarter than any other child I have seen.

  5. Haha why dont you try a study based on the effects of only using cannabis next time if you want actual “proof” that there is any sort of damage to the fetus. To assume that a person using cannabis is also drinking is ignorant, especially when pregnant. Also, these are mice. Try taking a poll from real women who have really used Cannabis for pregnancy pains. Cannabis is a medicine and causes far less harm than any of the prescription man-made drugs you could administer a pregnant woman for severe nausea, sleeplessness, aches and pains, anxiety, depression, etc. I have known plenty of women who have used Cannabis throughout their pregnancies, and not a single one of their children suffers any sort of defect. They tend to be happier, more well rounded children overall from interacting with them. Be honest; this is just another false study that shows no real evidence against cannabis use during pregnancy. You can’t get accurate results when you mix alcohol in there, and when you use mice as test subjects. Try again with a real study.

  6. This is an interesting new study. Its imp and hopefully we have more such studies done by these kind of independent, grant funded research institutions on Therapeutic benefits of CBD and also side effects if any or drug interactions. However we should have basic knowledge to understand and know that during pregnancy its advisable a woman does not drink alchohol, or smoke cigarretes or smoke weed or be on high pain killers or in this case CBD.

    This study does not explain what cbd and THC ratio was used and nor explains what dosage strength was used and for how long?

  7. Why?!?! What is your point to this article??? Stop policing the world with fear and blind ignorance because you only live in a primitive 3D world and really have no idea. Step out into the real world and you will notices the only people still trying to police the world are humans bond and demand to be stuck in a old way of life. And stop fucking testing your theories on animals just to get more funding for your bogus out dated science. Evole or Die. Sad science is controlled by corporate greed. No one cares anymore.

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