Using cannabis during pregnancy reduces the expression of immune-activating genes in the placenta, resulting in higher levels of anxiety, aggression, and hyperactivity in children by the time they reach six years of age.
The research involved 322 mother-child pairs who took part in a long-term study into stress in pregnancy.
An analysis of the youngsters’ hair also revealed higher levels of the stress hormone cortisol in those that had been exposed to cannabis while in the womb.
RNA sequencing revealed a reduction in the expression of genes associated with immune system function in the placentas of women who used cannabis during their pregnancies.