Will Prenatal Cannabis Use Cause Mental Delays on a Developing Brain?

Whether or not cannabis use during pregnancy causes physical, cognitive, or mental impairments later in life has been something scientists and researchers have been investigating for decades. Unfortunately, much of the research conducted thus far have not shown the whole picture or clinical implications for children in real life.

This has led medical and legal professionals to draft and base their policies on individual studies that do not truly show conclusive results. Because of this, a select group of researchers recently reviewed hundreds of studies regarding prenatal cannabis use and its effect on the child later in life to try to provide definitive answers regarding whether or not prenatal cannabis use does or does not cause issues later in life.

How Researchers Performed The Review

The study is titled “Totality Of The Evidence Suggests Prenatal Cannabis Exposure Does Not Lead To Cognitive Impairments: A Systematic A Critical Review.” Researchers noted the reason for this systematic and critical review is due to the “limited data demonstrating pronounced negative effects of prenatal cannabis exposure.” Within the background of the study, they also noted that public policies and popular opinion still reflect a belief that “cannabis is fetotoxic.” The results of their research concluded that the “cognitive performance scores of cannabis exposed groups overwhelmingly fell within the normal range when compared against normative data adjusted for age and education”, leading researchers to conclude that the belief that cannabis is fetotoxic when consumed during pregnancy is untrue.

The Search Strategy and Organization Model Utilized

To come to this conclusion, researchers utilized a search strategy that aimed to “identify research regarding the effects of prenatal cannabis exposure on cognitive abilities within humans” published prior to December 2017. To be included in the review, research had to be in the form of a full-text publication within a peer-reviewed journal, written in English, it must have assessed cognitive consequences of prenatal cannabis exposure and must have provided “quantitative measurement of cognitive performance.” Any studies that relied solely on brain imaging data or questionnaires were excluded from the review.

The research utilized in the analysis was further categorized based on the age in which the study assessed cognitive function within participants. These categories included infants and toddlers between birth and two years of age, children between the ages of 3 and 9, and early adolescents between the ages of 9 and 12, as well as adolescents and early adults from ages 13 to 22 years old.

What The Results Concluded

In general, cognitive performance was statistically different in only 4% of measurements; in 3.4%, the performance of cannabis exposed individuals was lower and in 1% it was higher.

The study states, “despite analyzing studies spanning approximately three decades, we conclude the evidence does not support an association between prenatal cannabis exposure and clinically relevant cognitive deficits.”

The research was conducted by Ciara A. Torres, Christopher Medina-Kirchner, Kate Y. O’Malley, and Carl L. Hart. The review was completed in the absence of any commercial or financial relationships that could have construed as a potential conflict of interest and was funded by the National Institute on Drug Abuse via grant #DA037801. Check out the full review here!