New research sheds light on the potential impact of cannabidiol (CBD) consumption during pregnancy on the development of offspring. A study conducted on mice revealed that fetal exposure to CBD could lead to altered development, affecting thermal pain sensitivity and problem-solving abilities in the offspring. These findings, published in Molecular Psychiatry, have implications for pregnant women who use CBD for its anti-nausea properties.
The nausea and vomiting experienced by many pregnant individuals, commonly known as morning sickness, can be quite debilitating. Some expectant mothers turn to cannabis for its anti-nausea properties, believing it to be safe. Cannabis contains two main components: cannabidiol (CBD) and tetrahydrocannabinol (THC). While THC is known for its psychoactive effects, CBD is not. Since the legalization of CBD in 2018, it has become widely available not only as part of cannabis but also as a standalone product.
CBD is known for its anti-nausea properties and is effective in alleviating nausea. However, the study aimed to understand the potential risks associated with fetal exposure to CBD and its impact on neurodevelopment.
“People take CBD to help with nausea, anxiety, pain, and trouble sleeping, which are common symptoms of pregnancy,” said study author Emily Bates, an associate professor at the University of Colorado Anschutz Medical Campus. “In fact, people recommended I take CBD to help with nausea during my own pregnancy. However, there was very little data published on how CBD affects fetal development.”
To explore the effects of fetal CBD exposure, researchers conducted a comprehensive study using female mice. They administered CBD to one group of pregnant mice and a control substance (sunflower oil) to another group, replicating measured oral CBD consumption. The dose used was equivalent to what the National Institute on Drug Abuse (NIDA) recommends for intraperitoneal injection in mice.
The study included 27 pregnant mice in each group, and the researchers closely monitored the animals throughout pregnancy. They tracked weight gain to ensure healthy fetal development, removing any mice that did not gain appropriate weight during pregnancy.
Blood samples from the mice were collected at different time points and analyzed to quantify CBD and its metabolites using specialized equipment. This allowed the researchers to confirm the presence of CBD and its breakdown products in the mice’s plasma.
The researchers found that male offspring who had been exposed to CBD during fetal development displayed increased sensitivity to thermal pain. This means they reacted more strongly to heat stimuli. This effect was linked to the TRPV1 receptor, which is activated by CBD and heat. Interestingly, the researchers found that this heightened sensitivity was not observed in female offspring.
On the other hand, female offspring who had been exposed to CBD during fetal development displayed reduced problem-solving abilities. This was assessed using the puzzle box test, which measures cognitive function associated with the prefrontal cortex. The study also revealed that fetal CBD exposure decreased the excitability of pyramidal neurons in the female prefrontal cortex. This effect was not observed in male offspring.
“These pre-clinical studies suggest that consumption of CBD during pregnancy is not without risks to the developing baby,” Bates told PsyPost. “People who are pregnant should consult with clinicians about best alternatives for treating nausea and other pregnancy symptoms.”
Contrary to previous studies fetal CBD exposure did not seem to significantly affect anxiety-like behaviors or compulsivity in the offspring. Multiple behavioral tests were conducted, including the open field test, light-dark box test, and elevated zero maze test. However, the results did not show any substantial differences between the CBD-exposed group and the control group in these aspects.
“We were surprised that gestational CBD exposure did not impact anxiety behaviors in mice because gestational cannabis exposure is associated with increased incidence of anxiety in humans and CBD activates a receptor that regulates anxiety,” Bates said. “However, we thoroughly tested anxiety and found no differences based on treatment.”
While this study provides valuable insights into the potential consequences of fetal CBD exposure, there are some important limitations to consider. Firstly, the research was conducted on mice, and the extent to which these findings apply to humans remains uncertain. Secondly, the study focused on a specific set of behaviors and physiological responses, and the broader impact of CBD exposure on neurodevelopment warrants further investigation. Additionally, the study used a specific dose of CBD, and different doses could produce different effects.
“Our studies were completed with very high doses of CBD to reveal any subtle effects of CBD on brain development,” Bates explained. “However, we are currently studying how maternal consumption of lower CBD doses affects offspring development.”
The study, “Fetal cannabidiol (CBD) exposure alters thermal pain sensitivity, problem-solving, and prefrontal cortex excitability“, was authored by Karli S. Swenson, Luis E. Gomez Wulschner, Victoria M. Hoelscher, Lillian Folts , Kamryn M. Korth, Won Chan Oh, and Emily Anne Bates.