Cannabis Use During Pregnancy May Affect Placenta, Stress, Anxiety, And Development In Children: Study

TORONTO – Cannabis use during pregnancy has become increasingly common over the past two decades, but a study released Monday suggests these children had higher levels of the stress hormone, as well as greater stress hormone levels. anxiety, aggressiveness and hyperactivity.

The peer-reviewed study, published in Proceedings of the National Academy of Science (PNAS), found a significant correlation between cannabis use during pregnancy and many aspects of early childhood development, the authors wrote.

“Pregnant women are bombarded with misinformation that cannabis is safe, when the reality is that cannabis is more potent today than it was a few years ago. Our results indicate that its use during pregnancy may have a long-term impact on children, ”said Yasmin Hurd, director of the Mount Sinai Institute of Addiction and lead author of the article, in a statement.

Under the direction of researchers at the Icahn School of Medicine at Mount Sinai and the City University of New York, 322 people who reported using cannabis during pregnancy and / or while breastfeeding were followed and the placenta removed after pregnancy. birth. They followed their children around the age of three to six.

The researchers measured the levels of hair hormones, heart rate variability (HRV) at rest and during auditory startle – a test for an unconditional reflex caused by an unexpected loud sound – of the children and examined their neurobehavioural traits. as measured on the Behavior Rating System. for the children’s survey.

Hair samples revealed higher levels of the stress hormone cortisol, as well as decreased normalized heart rate variability. HRV generally decreases during stress and is considered a marker of autonomic nervous system function and stress sensitivity. High levels of anxiety, aggression and hyperactivity were also measured in young children, according to the study.

The placenta of some of the children who underwent behavioral assessments was processed for RNA sequencing, as scientists found that cannabis use during pregnancy was associated with lower expression of immune-activating genes, including Pro-inflammatory cytokines and immune cell type markers that help protect against pathogens.

“Using gene co-expression analysis, we revealed networks of immune system-related genes in the placenta significantly correlated with anxiety and hyperactivity problems,” the authors wrote.

“Consistent with previous surveys reporting an increased risk of psychiatric illness in children exposed to prenatal cannabis, the present study showed that [maternal cannabis use] is associated with increased anxiety, aggression and hyperactivity in young children. In addition, with several altered psychobehavioural traits, [these] the children presented endocrine and physiological phenotypes compatible with aberrant regulation of stress and anxiety.