Researchers Say CBD And THC Use During Early Pregnancy Can Disrupt Fetal Development

Researchers at UNC School of Medicine have published a study in Scientific Reports showing how a single exposure to cannabinoids (CBs) during pregnancy can cause growth issues in a developing embryo; the first research to demonstrate the connection in mammals.

The research was performed using mice as they are accurate models for the development that takes place during pregnancy.

Researchers also tested a synthetic cannabinoid in zebrafish that, according to the study’s senior author, Scott Parnell, Ph.D., yielded similar growth deformations as the natural CBs.

Parnell says that having the same results across animal models reinforces their findings.

According to researchers, the brain and facial developmental effects that manifested after a one-time exposure to cannabidiol (CBD) and delta-9 tetrahydrocannabinol (THC) were similar to what is seen in fetal alcohol syndrome.

The research team says that when CBs and alcohol were used together, the likelihood of the birth defects more than doubled, showing that the drugs may cause defects by interacting on a cellular level and disrupting signals between molecules and cells that control growth and development.

“The interaction between alcohol and CBs we witnessed is very concerning,” says UNC School of Medicine Bowles Center for Alcohol Studies research associate Eric Fish. “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.”

During the study, CBs and CBs with alcohol were administered in varying amounts on the eighth day of pregnancy, which is comparable to weeks three and four in human mothers and a time when alcohol and CB exposure poses exceptional developmental risks.

CBD was administered in amounts that would be considered therapeutic and the THC concentration administered was comparable to levels reached by smoking cannabis.

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

Parnell and Fish say that they now plan to test multiple smaller exposures throughout a pregnancy to better mimic regular cannabis use by a human during pregnancy.