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
Scientists Flip a Gut Virus “Kill Switch” – Expose a Hidden Threat in Antibiotic Treatment
Scientists have long known that bacteriophages, viruses that infect bacteria, live in our gut, but exactly what they do has remained elusive. Researchers developed a clever mouse model that can temporarily eliminate these phages [...]
Enhanced Antibacterial Polylactic Acid-Curcumin Nanofibers for Wound Dressing
Background Wound healing is a complex physiological process that can be compromised by infection and impaired tissue regeneration. Conventional dressings, typically made from natural fibers such as cotton or linen, offer limited functionality. Nanofiber [...]
Global Nanomaterial Regulation: A Country-by-Country Comparison
Nanomaterials are materials with at least one dimension smaller than 100 nanometres (about 100,000 times thinner than a human hair). Because of their tiny size, they have unique properties that can be useful in [...]
Pandemic Potential: Scientists Discover 3 Hotspots of Deadly Emerging Disease in the US
Virginia Tech researchers discovered six new rodent carriers of hantavirus and identified U.S. hotspots, highlighting the virus’s adaptability and the impact of climate and ecology on its spread. Hantavirus recently drew public attention following reports [...]
Studies detail high rates of long COVID among healthcare, dental workers
Researchers have estimated approximately 8% of Americas have ever experienced long COVID, or lasting symptoms, following an acute COVID-19 infection. Now two recent international studies suggest that the percentage is much higher among healthcare workers [...]
Melting Arctic Ice May Unleash Ancient Deadly Diseases, Scientists Warn
Melting Arctic ice increases human and animal interactions, raising the risk of infectious disease spread. Researchers urge early intervention and surveillance. Climate change is opening new pathways for the spread of infectious diseases such [...]
Scientists May Have Found a Secret Weapon To Stop Pancreatic Cancer Before It Starts
Researchers at Cold Spring Harbor Laboratory have found that blocking the FGFR2 and EGFR genes can stop early-stage pancreatic cancer from progressing, offering a promising path toward prevention. Pancreatic cancer is expected to become [...]
Breakthrough Drug Restores Vision: Researchers Successfully Reverse Retinal Damage
Blocking the PROX1 protein allowed KAIST researchers to regenerate damaged retinas and restore vision in mice. Vision is one of the most important human senses, yet more than 300 million people around the world are at [...]
Differentiating cancerous and healthy cells through motion analysis
Researchers from Tokyo Metropolitan University have found that the motion of unlabeled cells can be used to tell whether they are cancerous or healthy. They observed malignant fibrosarcoma [...]
This Tiny Cellular Gate Could Be the Key to Curing Cancer – And Regrowing Hair
After more than five decades of mystery, scientists have finally unveiled the detailed structure and function of a long-theorized molecular machine in our mitochondria — the mitochondrial pyruvate carrier. This microscopic gatekeeper controls how [...]
Unlocking Vision’s Secrets: Researchers Reveal 3D Structure of Key Eye Protein
Researchers have uncovered the 3D structure of RBP3, a key protein in vision, revealing how it transports retinoids and fatty acids and how its dysfunction may lead to retinal diseases. Proteins play a critical [...]
5 Key Facts About Nanoplastics and How They Affect the Human Body
Nanoplastics are typically defined as plastic particles smaller than 1000 nanometers. These particles are increasingly being detected in human tissues: they can bypass biological barriers, accumulate in organs, and may influence health in ways [...]
Measles Is Back: Doctors Warn of Dangerous Surge Across the U.S.
Parents are encouraged to contact their pediatrician if their child has been exposed to measles or is showing symptoms. Pediatric infectious disease experts are emphasizing the critical importance of measles vaccination, as the highly [...]
AI at the Speed of Light: How Silicon Photonics Are Reinventing Hardware
A cutting-edge AI acceleration platform powered by light rather than electricity could revolutionize how AI is trained and deployed. Using photonic integrated circuits made from advanced III-V semiconductors, researchers have developed a system that vastly [...]
A Grain of Brain, 523 Million Synapses, Most Complicated Neuroscience Experiment Ever Attempted
A team of over 150 scientists has achieved what once seemed impossible: a complete wiring and activity map of a tiny section of a mammalian brain. This feat, part of the MICrONS Project, rivals [...]
The Secret “Radar” Bacteria Use To Outsmart Their Enemies
A chemical radar allows bacteria to sense and eliminate predators. Investigating how microorganisms communicate deepens our understanding of the complex ecological interactions that shape our environment is an area of key focus for the [...]
