As cannabis legalization expands across various regions, more pregnant women are using cannabis, particularly for relief from morning sickness, back pain, and anxiety, Earth.com reports.
Recent data suggest that up to 1 in 5 pregnant women in the United States now use cannabis, with tetrahydrocannabinol (THC), the primary psychoactive ingredient, being a common component. However, emerging research indicates that THC exposure during pregnancy may pose significant risks to the developing fetus.
A recent preclinical animal study, conducted by researchers at the University of Maryland School of Medicine and published in Science Advances, explored the effects of prenatal THC exposure on the developing brain. The study revealed that THC exposure could rewire the fetal brain, particularly impacting the reward system.
According to the study, THC exposure led to hyperactivity in dopamine-producing neurons in the fetal brain, which in turn resulted in an increased release of dopamine. This was particularly significant in response to reward-related stimuli, such as the presence of food or drugs like opioids. Researchers found that even moderate doses of THC—equivalent to one or two joints per day in humans—could alter how the fetal brain processes rewards, fostering behaviors linked to increased opioid-seeking.
The study noted that these changes were particularly pronounced in male animals, who exhibited a stronger response to opioid exposure during adolescence compared to their non-exposed counterparts. These findings support the theory of a “hypersensitized” reward system, which may increase vulnerability to addiction later in life.
Dr. Joseph Cheer, a professor of Neurobiology and Psychiatry at the University of Maryland, emphasized that the increased potency of modern cannabis, with THC content up to four times higher than previous generations, is contributing to these risks. He noted that prenatal exposure to THC could have long-term consequences for the brain’s reward system, potentially heightening the risk of opioid addiction.
The research raises critical questions about the long-term effects of prenatal THC exposure, particularly its role in opioid addiction. Dr. Cheer and his colleague, Dr. Mary Kay Lobo, co-direct the Center for Substance Use in Pregnancy at the University of Maryland, where they continue to explore these issues. Their research aims to understand whether some of the negative effects of THC exposure could be mitigated through advanced therapies like CRISPR gene editing or the repurposing of existing drugs.
Additionally, the study highlighted that many pregnant women may turn to cannabis, believing it to be a safer alternative to prescription medications, such as anti-anxiety drugs. This perception underscores the need for clearer guidance and more robust public health education on the potential risks of cannabis use during pregnancy.
While cannabis has been shown to provide benefits for conditions such as chronic pain, anxiety, and nausea in non-pregnant individuals, its effects during pregnancy remain a concern. Previous studies have linked prenatal cannabis exposure to deficits in attention, memory, and cognitive functioning in children, as well as increased risks of low birth weight, which can lead to developmental delays and other health complications.
As cannabis use becomes more common among pregnant women, there is a growing need for comprehensive public health programs to educate expectant mothers about the potential long-term effects of THC exposure. Future research, particularly studies involving human participants, will be essential to understanding how prenatal cannabis use impacts fetal brain development and what interventions may be necessary to reduce harm.
