Maternal cannabis use and fetal and child development

Maternal cannabis use and fetal and child development

As legalization of cannabis for recreational use spreads, the drug’s use during pregnancy is increasing. However, the impact of maternal cannabis use on fetal and childhood development is unclear.

The researchers examined placental gene expression and early childhood behavior and physiology in a long-term study of 322 mother–child pairs residing in New York City.

When the children were approximately 3–6 years old, hormone levels in their hair samples were measured, and their behavioral and emotional functioning was assessed based on surveys administered to the parents.

The children of mothers who used cannabis during pregnancy showed higher anxiety, aggression, hyperactivity, and levels of the stress hormone cortisol, compared with children of mothers who did not use cannabis during pregnancy.

Analysis of placental tissue collected from a subset of participants showed that maternal cannabis use was associated with lower expression of many immune-activating genes, including those involved in proinflammatory cytokine signaling and protection against pathogens.

The cannabis-related reduction in placental immune signaling was linked to increased anxiety and hyperactivity.

According to the authors, the results suggest that placental immune suppression related to maternal cannabis use may increase the risk of mental health problems in early childhood.