Are there Pregnancy Risks from CBD? New Study Provides Insights

As cannabis legalization continues to expand worldwide, many individuals perceive it as a relatively safe substance.  While this may be the case in certain instances, it is crucial to recognize that certain subsets of the population need to be more mindful of their consumption habits.  Primary among these are pregnant women using cannabis – especially cannabidiol (CBD) – to manage nausea, anxiety, and sleep issues.  While alleviating these symptoms may be enticing, emerging research has raised various concerns about the impact of prenatal cannabis exposure on fetal development and long-term health outcomes.

A new study¹ conducted by McMaster University has provided more reason for concern with findings that suggest cannabis consumption during pregnancy may pose risks to both mother and child.

Details of the Study

The McMaster study investigated the effects of oral tetrahydrocannabinol (THC) and cannabidiol (CBD) exposure during pregnancy using a mouse model.  The researchers found that prenatal exposure to these cannabinoids resulted in multiple adverse outcomes, including:

Impaired Fetal Growth

One of the most concerning findings was that fetuses exposed to cannabis were significantly smaller than those in the control group.  Restricted fetal growth is often linked to developmental complications, an increased risk of stillbirth, and potential long-term health issues such as obesity, cardiovascular disease, and cognitive impairments.

Placental Abnormalities

The study also found that cannabinoids disrupted the development of placental blood vessels, reducing their ability to transport nutrients and oxygen efficiently.  Proper placental function is critical for fetal development, and any disruption can lead to complications such as preterm birth, low birth weight, and neurodevelopmental disorders.

Behavioral Changes in Offspring

Postnatal evaluations of mice exposed to cannabis in utero revealed notable behavioral changes, including heightened aggression, hyperactivity, and learning difficulties.  These findings align with previous research suggesting that prenatal cannabis exposure can alter neurodevelopment, potentially increasing the risk of attention-deficit/hyperactivity disorder (ADHD) and other cognitive deficits in children.

Additional Evidence on Prenatal Cannabis Exposure

It should be noted that the McMaster study is not the first of its kind to raise concerns about the risks of prenatal cannabis exposure.  Other research studies have found similar effects, reinforcing a need for better awareness of when cannabis consumption is and isn’t safe.

Prenatal Cannabis Exposure and Genetic Changes

Recent research² suggests that prenatal cannabis exposure can cause genetic changes in children, potentially leading to altered gene expression and an increased likelihood of developing various health conditions.  These genetic modifications may influence brain development, immune function, and even susceptibility to psychiatric disorders later in life.

Increased Risk of Opioid Addiction

One of the more alarming findings in cannabis-related research³ is its potential link to opioid addiction.  A separate study found that individuals exposed to cannabis in utero exhibited a greater likelihood of developing opioid dependency later in life.  This raises concerns that prenatal cannabis exposure may alter neural pathways associated with addiction, making affected individuals more vulnerable to substance use disorders.

Cannabinoid Transmission Through Breast Milk

Another aspect of concern is the persistence of cannabinoids in breast milk.  Studies⁴ have shown that THC and other cannabinoids can be transmitted to infants through breastfeeding, exposing them to potential neurodevelopmental risks even after birth.  The long-term effects of such exposure remain unclear, but the presence of psychoactive compounds in breast milk suggests that infants may experience altered brain development and behavioral outcomes.

The Potential Benefits of Cannabis Use During Pregnancy

While recent research highlights numerous risks, it should be noted that most of these studies have not been completed on human subjects.  For the time being, many feel that cannabis continues to offer relief for certain issues in situations where other medications may be even more harmful.

Despite this potentially being true, it is crucial that anyone considering consuming cannabis while pregnant first consult with a healthcare professional.  The potential risks must be weighed carefully against any perceived advantages.

Nausea and Vomiting Relief

Many pregnant women experience severe nausea and vomiting, commonly known as hyperemesis gravidarum.  Traditional anti-nausea medications may not work for everyone, and cannabis has been reported to provide effective relief for those suffering from extreme morning sickness.

Anxiety and Sleep Aid

Pregnancy can be an emotionally taxing time, leading to heightened anxiety and sleep disturbances.  Some have found relief from CBD, as it helps them manage anxiety without the intoxicating effects of THC, potentially reducing stress-related complications during pregnancy.

Pain Management

For pregnant women dealing with chronic pain, such as migraines or back pain, cannabis has been used as an alternative pain reliever.  Traditional pain medications, such as opioids, come with their own risks, and some women opt for cannabis as a perceived safer alternative.

The Worrying Trend of Cannabis Use Among Pregnant Women

Despite increasing awareness of the risks, cannabis use during pregnancy remains alarmingly high. A recent survey⁵ found that nearly 6% of pregnant women admitted to using cannabis, often believing it to be a natural and safe remedy for morning sickness and anxiety.  This misconception persists despite growing scientific evidence linking prenatal cannabis exposure to developmental and behavioral problems in children.

A significant factor contributing to continued use is the widespread availability of CBD products.  Many women assume that CBD, a non-psychoactive cannabinoid, is harmless.  However, as the McMaster study indicates, even CBD exposure during pregnancy can have detrimental effects, including impaired fetal growth and placental dysfunction.

Conclusion

The findings from this most recent study add to a growing body of evidence highlighting the dangers of prenatal cannabis exposure.  From impaired fetal growth and placental dysfunction to behavioral changes and potential genetic alterations, the risks are substantial and warrant serious consideration.  Despite this, cannabis use among pregnant women remains prevalent, largely due to misinformation and the perceived safety of CBD products.

Ultimately, while cannabis may offer therapeutic benefits in many situations, its use during pregnancy remains a high-risk choice—one that expectant mothers should approach with caution and thorough medical consultation.

Study Reference:

^{1. Ward, A. (2025, February 6). Is CBD use during pregnancy as safe as people think? New study uncovers potential risks to babies. McMaster University Faculty of Health Sciences. https://healthsci.mcmaster.ca/is-cbd-use-during-pregnancy-as-safe-as-people-think-new-study-uncovers-potential-risks-to-babies/}

^{2. Cao-Lei, L., de Rooij, S. R., King, S., Matthews, S. G., Metz, G. A. S., Roseboom, T. J., & Szyf, M. (2024). Prenatal cannabis exposure is associated with alterations in offspring DNA methylation at genes involved in neurodevelopment, across the life course. Molecular Psychiatry. https://www.nature.com/articles/s41380-024-02752-w}

^{3. Luján, M. Á., Young-Morrison, R., Aroni, S., Katona, I., Melis, M., & Cheer, J. F. (2024). Dynamic overrepresentation of accumbal cues in food- and opioid-seeking rats after prenatal THC exposure. Science Advances, 10(eadq5652). https://doi.org/10.1126/sciadv.adq5652}

^{4. Belfort, M. B., Guillet, R., & Newman, J. (2024). Human milk cannabinoid concentrations and associations with maternal cannabis use. Breastfeeding Medicine. https://doi.org/10.1089/bfm.2024.0021}

^{5. Haider, M. R., Karim, S., Jayawardhana, J., Hansen, N. B., & Haile, Z. T. (2024). Association between state-level medical marijuana legalization and marijuana use during pregnancy: A population-based study. The American Journal on Addictions, 34(1), 75–84. https://doi.org/10.1111/ajad.13651}