CBD is gaining popularity as a remedy for pregnancy symptoms like nausea and anxiety, but new research suggests it may not be as safe as many believe.
A study from McMaster University found that oral cannabis use, including both THC and CBD, is linked to impaired fetal growth, abnormal placental development, and long-term behavioral changes in offspring.
CBD Use in Pregnancy: Research Uncovers Potential Risks
Cannabidiol (CBD), a compound in cannabis often used for therapeutic purposes, is becoming increasingly popular among pregnant individuals to help manage symptoms like nausea, anxiety, and sleep disturbances. While many believe that CBD — especially when taken orally — is a safer option, research on its effects during pregnancy remains limited.
A new study from researchers at McMaster University sheds light on this knowledge gap, revealing potential risks linked to both CBD and tetrahydrocannabinol (THC), the psychoactive component of cannabis. The findings suggest that using these substances during pregnancy may impair fetal growth and development.
Published today (February 5, 2025) in eBioMedicine, part of The Lancet Discovery Science, the study found that oral cannabis use from early to mid-pregnancy was associated with restricted fetal growth, changes in placental development, and long-term effects on offspring behavior, including altered aggression, activity levels, and learning ability.
Perception vs. Reality: Is CBD Really Safe?
“The use of cannabis during pregnancy is rising in Canada. Most previous studies focus on exposure to cannabis smoke or just the psychoactive component of cannabis (THC), leaving other cannabis ingredients and methods of consumption understudied. However, consuming cannabis orally or only using other cannabis ingredients like CBD, is often perceived as safer despite this lack of evidence. Our study is shedding light that there’s a possibility that CBD might also be harmful in the pregnancy,” says Tyrah Ritchie, who led the study while completing her master’s degree in the Medical Sciences program at McMaster University and with the McMaster Immunology Research Centre.
Cannabis Use May Impact Growth and Behavior
The group of scientists led by Ritchie and Ali Ashkar, professor with McMaster’s Department of Medicine, conducted the research by administering cannabis oil to mouse models and followed the development of the fetuses during pregnancy and post-birth.
The researchers found that both THC and CBD impaired fetal growth causing fetuses to be small when compared to mice that did not receive cannabis. Additionally, they found that both THC and CBD impact the development of the blood vessels that supply the placenta and therefore the baby with nutrients.
“We did see that both THC and CBD can disrupt a special type of immune cell called a Uterine NK Cell that is crucial in normal development of the placenta. We also saw poor development of the arteries that help supply blood to the placenta. We’re thinking this is what is possibly disrupting the nutrient and oxygen delivery to the baby and contributing to the intrauterine growth restriction,” says Ashkar.
Long-Term Effects on Offspring Behaviour
When observing the behavior of the babies post-birth, researchers found changes in their aggression, activity levels, and even learning ability.
“Oral use of THC and CBD during the pregnancy not only disrupts the growth of the baby but seems to have long-term consequences as the babies were found to have changes in their behavior later in life,” says Ritchie.
More Research Needed on CBD and Pregnancy
Ritchie says more research is needed to better understand the impacts of cannabis in humans during pregnancy, but says this study shows the possibility of it being dangerous or harmful.
Reference: “The impact of oral cannabis consumption during pregnancy on maternal spiral artery remodelling, fetal growth and offspring behaviour in mice” by Tyrah M. Ritchie, Emily Feng, Fatemeh Vahedi, Sofya Ermolina, Christian J. Bellissimo, Erica De Jong, Ana L. Portillo, Sophie M. Poznanski, Lauren Chan, Sara M. Ettehadieh, Deborah M. Sloboda, Dawn M.E. Bowdish and Ali A. Ashkar, 5 February 2025, eBioMedicine.
DOI: 10.1016/j.ebiom.2025.105572
Funding for the study was provided by The Michael G. DeGroote Centre for Medicinal Cancer Research, the Canadian Institutes of Health Research, and the Canadian Foundation for Innovation.
News
New Study Challenges Beliefs About CBD in Pregnancy, Reveals Unexpected Risks
CBD is gaining popularity as a remedy for pregnancy symptoms like nausea and anxiety, but new research suggests it may not be as safe as many believe. A study from McMaster University found that [...]
Does COVID increase the risk of Alzheimer’s disease?
Scientists discover that even mild COVID-19 can alter brain proteins linked to Alzheimer’s disease, potentially increasing dementia risk—raising urgent public health concerns. A recent study published in the journal Nature Medicine investigated whether both mild and [...]
New MRI Study Reveals How Cannabis Alters Brain Activity and Weakens Memory
A massive new study sheds light on how cannabis affects the brain, particularly during cognitive tasks. Researchers analyzed over 1,000 young adults and found that both heavy lifetime use and recent cannabis consumption significantly reduced brain [...]
How to Assess Nanotoxicity: Key Methods and Protocols
With their high surface area and enhanced physicochemical properties, nanomaterials play a critical role in drug delivery, consumer products, and environmental technologies. However, their nanoscale dimensions enable interactions with cellular components in complex and [...]
Nanotech drug delivery shows lasting benefits, reducing need for repeat surgeries
A nanotechnology-based drug delivery system developed at UVA Health to save patients from repeated surgeries has proved to have unexpectedly long-lasting benefits in lab tests – a promising sign for its potential to help human patients. [...]
Scientists Just Found DNA’s Building Blocks in Asteroid Bennu – Could This Explain Life’s Origins?
Japanese scientists detected all five nucleobases — building blocks of DNA and RNA — in samples returned from asteroid Bennu by NASA’s OSIRIS-REx mission. NASA’s OSIRIS-REx mission brought back 121.6 grams of asteroid Bennu, unveiling nitrogen-rich organic matter, including DNA’s essential [...]
AI-Designed Proteins – Unlike Any Found in Nature – Revolutionize Snakebite Treatment
Scientists have pioneered a groundbreaking method to combat snake venom using newly designed proteins, offering hope for more effective, accessible, and affordable antivenom solutions. By utilizing advanced computational techniques and deep learning, this innovative [...]
New nanosystem offers hope for improved diagnosis and treatment of tongue cancer
A pioneering study has unveiled the Au-HN-1 nanosystem, a cutting-edge approach that promises to transform the diagnosis and treatment of tongue squamous cell carcinoma (TSCC). By harnessing gold nanoparticles coupled with the HN-1 peptide, [...]
Global Trust in Science Is Stronger Than Expected – What’s Next?
A landmark global survey conducted across 68 countries has found that public trust in scientists remains robust, with significant support for their active involvement in societal and political matters. The study highlights the public’s [...]
Microplastics in the bloodstream may pose hidden risks to brain health
In a recent study published in the journal Science Advances, researchers investigated the impact of microplastics on blood flow and neurobehavioral functions in mice. Using advanced imaging techniques, they observed that microplastics obstruct cerebral blood [...]
AI Surveillance: New Study Exposes Hidden Risks to Your Privacy
A new mathematical model enhances the evaluation of AI identification risks, offering a scalable solution to balance technological benefits with privacy protection. AI tools are increasingly used to track and monitor people both online [...]
Permafrost Thaw: Unleashing Ancient Pathogens and Greenhouse Gases
Permafrost is a fascinating yet alarming natural phenomenon. It refers to ground that remains frozen for at least two consecutive years. Mostly found in polar regions like Siberia, Alaska, and Canada, permafrost plays a [...]
Frequent social media use tied to higher levels of irritability
A survey led by researchers from the Center for Quantitative Health at Massachusetts General Hospital and Harvard Medical School has analyzed the association between self-reported social media use and irritability among US adults. Frequent [...]
Australian oysters’ blood could hold key to fighting drug-resistant superbugs
Protein found in Sydney rock oysters’ haemolymph can kill bacteria and boost some antibiotics’ effectiveness, scientists discover An antimicrobial protein found in the blood of an Australian oyster could help in the fight against [...]
First U.S. H5N1 Death Sparks Urgency: Scientists Warn Bird Flu Is Mutating Faster Than Expected
A human strain of H5N1 bird flu isolated in Texas shows mutations enabling better replication in human cells and causing more severe disease in mice compared to a bovine strain. While the virus isn’t [...]
AI Breakthrough in Nanotechnology Shatters Limits of Precision
At TU Graz, a pioneering research group is leveraging artificial intelligence to drastically enhance the way nanostructures are constructed. They aim to develop a self-learning AI system that can autonomously position molecules with unprecedented precision, potentially [...]
