Exposure to cannabis during pregnancy has a significant impact on placental and fetal development

Research shows the real risks associated with cannabis exposure during pregnancy.


Over the last decade, cannabis use has progressively increased in pregnant women, in part due to the perception that its usage poses no risk in perinatal life. 1 in 5 women report cannabis use during pregnancy, with nausea cited as their primary motivation.

Many studies have suggested that the use of cannabis causes fetal growth restriction, though the mechanisms are not well understood.

Now a new study by Queen’s University and Western University examines the impact of cannabis exposure during pregnancy on fetal development, neonatal outcomes, and placental development.

David Natale, Associate Professor at Queen’s and co-author on the paper, said, “Marijuana has been legalized in Canada, and in many states in the US, however, its use during pregnancy has not been well studied up until this point. This study is important to support clinicians in communicating the genuine risks associated with cannabis use during pregnancy.”

This is the first study that shows regular exposure to THC, the primary psychoactive ingredient in cannabis, during pregnancy has a significant impact on placental and fetal development.

The study was conducted on rat models that demonstrate regular exposure to a low-dose of THC that mimics daily use of cannabis during pregnancy led to a reduction in birth weight of eight percent and decreased brain and liver growth by more than 20 percent. Scientists also characterized how THC prevents oxygen and nutrients from crossing the placenta into the developing fetus.

The study is published today in Scientific Reports.

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