Use of cannabidiol (CBD) while pregnant may impair fetal growth, trigger changes in the placenta, and lead to changes in aggression, activity levels, and learning ability in offspring, found a new study. The findings were published in eBioMedicine.
“The use of cannabis during pregnancy is rising in Canada. Most previous studies focus on exposure to cannabis smoke or just the psychoactive component of cannabis (THC), leaving other cannabis ingredients and methods of consumption understudied,” said lead author of the study, Tyrah Ritchie, who completed her master's degree at McMaster University and with the McMaster Immunology Research Centre, in a press release.
"However, consuming cannabis orally or only using other cannabis ingredients like CBD, is often perceived as safer despite this lack of evidence. Our study is shedding light that there's a possibility that CBD might also be harmful in the pregnancy,” she added.
In the current study, researchers investigated how safe it is to use oral CBD and tetrahydrocannabinol (THC) during pregnancy. To do so, they compared the effects of oral CBD and THC oil exposure from early to mid-gestation in mouse models. They followed the development of fetuses during pregnancy and after they were born.
Ultimately, both THC and CBD were found to impair fetal growth compared to mice not exposed to cannabis. Both substances also impacted the development of blood vessels that supply the placenta and, thus, the offspring with nutrients.
“We did see that both THC and CBD can disrupt a special type of immune cell called a Uterine NK Cell that is crucial in normal development of the placenta. We also saw poor development of the arteries that help supply blood to the placenta. We're thinking this is what is possibly disrupting the nutrient and oxygen delivery to the baby and contributing to the intrauterine grow restriction,” said Ali Ashkar, professor at the Department of Medicine at McMaster University, in a press release.
The researchers also observed long-lasting sex-dependent effects as male offspring displayed altered aggression and metabolic activity while females exhibited impaired spatial learning.
Ritchie noted that more research is needed into how cannabis impacts humans during pregnancy. She noted, however, that the present study highlights the possibility of it being harmful or dangerous.
SourcesL EurekAlert, eBioMedicine
