2. Study on Cannabis and Child Development

Studies on pregnancy and child health: An innovative focus on cannabis

Led by Professor Gina Muckle and pediatrician/professor Richard E. Bélanger, our research team documents factors that influence child health and development, with a particular focus on the effects of cannabis use during pregnancy. While the harmful effects of alcohol and tobacco consumption during pregnancy are widely recognized, those of cannabis are yet to be fully understood. Δ9-Tetrahydrocannabinol (THC), the primary active constituent of cannabis, can easily cross the placental barrier to reach the fetus, which is sensitive to environmental changes due to its immaturity. High concentrations of THC can also be found in breastmilk. As the use of cannabis and its perceived safety have both increased since it was legalized in Canada in 2019, it is crucial to determine whether it has negative effects on pregnancy and child health.

The primary objective of this study, led by Professor Muckle, is to evaluate the impact of cannabis exposure on several aspects of children’s development and behaviour up to the age of 30 months. The study will also help paint an up-to-date portrait of cannabis use by couples during pregnancy and in the years following, as well as evaluating the incidence of prenatal cannabis exposure on complications during pregnancy, newborn health and the child’s physical growth. We will also explore whether some factors, like maternal diet and stress, impact the effects of cannabis.

This study uses an innovative method to measure fetal exposure to cannabis (hair samples), which reduces the margin for error associated with questionnaire-based data on frequency of cannabis use. With the rigorous data that it will provide, this study’s results will help guide parents and the practices of both professionals and organizations that work with pregnant women and parents, in addition to supporting preventative public health actions and government policy.

The clinical phase of prenatal data collection was carried out at the CHU de Québec/Université Laval Research Centre by professor and obstetrician Dr. Emmanuel Bujold, thanks to the centre’s clinical research infrastructure. Our other partners are the Institut national de santé publique du Québec and its laboratory, the Centre de toxicologie du Québec, and the Québec Ministry of Health and Social Services.

Primary research team : Muckle, Gina^1,9; Bélanger, Richard^2,9

Co-researchers : Ayotte, Pierre³; Boivin, Michel¹; Bujold, Emmanuel^4,9; Chaillet, Nils^4,9; Haddad, Sami⁸; Marc, Isabelle^2,9; Matte-Gagné, Célia^1,5,9; Morisset, Anne-Sophie^6,9; Ouellet-Morin, Isabelle⁷; Petitclerc, Amélie M¹; Piedboeuf, Bruno^2,9; Tarabulsy, George^1,5