CBD can disrupt fetal development: One-time exposure can cause brain and facial birth defects, mouse study finds

06 Nov 2019 --- One-time exposure to cannabinoids (CBs) – both synthetic and natural – during early pregnancy, can cause growth issues in developing embryos. This is according to a new study by the University of North Carolina (UNC) School of Medicine published in Scientific Reports. It found that components of marijuana, including cannabidiol (CBD) and tetrahydrocannabinol (THC), can cause brain and facial birth defects if used during the first trimester. The study comes as CBD’s soaring popularity is translating in NPD, albeit amid a hazy regulatory environment. The US Food and Drug Administration (FDA), however, has “strongly advised” against the use of CBD, THC and marijuana in any form during pregnancy.

“The development of the embryo in this time period is very similar across all vertebrates,” says senior author, Scott Parnell, Ph.D., Assistant Professor of Cell Biology and Physiology at the UNC School of Medicine. “In this study, we also test a synthetic cannabinoid in zebrafish that yielded similar growth deformations as the natural CBs. Having the same results across animal models reinforces our findings.”

CBD products are continuously emerging with industry witnessing CBD-infused wines, chocolates and ice creams product development. However, its use is still not completely hurdle-free from a regulatory aspect and the FDA has yet to set a clear framework that will allow the straightforward use of CBD in NPD. Concerns over its safety, especially during tender times such as pregnancy, are mounting and more research is looking into its potentially adverse side effects.

There is no comprehensive research studying the effects of CBD on the developing fetus, pregnant mother or breastfed baby. The FDA is continuing to collect and study the data on the possible harmful effects of CBD during pregnancy and while breastfeeding. “However, based on what we do know so far, there is a significant cause for concern,” says the FDA. 

The US Food and Drug Administration (FDA) strongly advises against the use of CBD, THC and marijuana in any form during pregnancy.High doses of CBD in pregnant test animals have caused problems with the reproductive system of developing male fetuses. The new study marks the first research to show a connection between pregnancy and CBs in mammals.

CBs similar to alcohol use?
The new study was performed in mice, which are very accurate models for the development that occurs during early pregnancy, according to Parnell. 

In this study, the brain and facial developmental effects caused by a one-time exposure to CBs are very similar to what is seen in fetal alcohol syndrome (FAS). Parnell and colleagues also found that when CBs and alcohol were used together, the likelihood of these birth defects more than doubled. They went on to show that these drugs may be causing defects by interacting on a basic cellular level and disrupting signaling between molecules and cells that control growth and development.

“The interaction between alcohol and CBs we witnessed is very concerning,” notes the study’s first author, Eric Fish, Ph.D., Research Associate in the UNC School of Medicine Bowles Center for Alcohol Studies. “Previous studies have shown that CBs and alcohol are frequently used together, and for pregnant women, we’re learning that could be very dangerous to a developing child.”

In the study, CBs and CBs with alcohol, were given in varying amounts on day eight of pregnancy, which is comparable to the third and fourth weeks of pregnancy in humans. This time period is when alcohol and CB exposure is especially damaging to a developing embryo and is before some women know they are pregnant. The CBD amounts administered were within what is considered a therapeutic range for humans. The THC concentration administered was similar to levels reached by a person smoking marijuana.

“It is concerning how little we know about the use of marijuana, its CBs, and products like CBD oil during pregnancy,” Parnell says. “We know that there is no safe period to drink alcohol during pregnancy and I think this research shows the same is likely true of marijuana use.”

With the results of these one-time exposures, Parnell and Fish are planning to now test smaller, multiple exposures throughout pregnancy that better mimics real-life usage in human pregnancy.

Edited by Kristiana Lalou