P renatal exposures to nicotine cigarettes (hereafter cigarettes), alcohol, cannabis, cocaine and opioids put children at risk for adverse outcomes including preterm birth, low birth weight, motor abnormalities, and mental health and cognitive problems. [1][2][3][4][5][6][7][8][9] Rates of prenatal substance use in Canada remain concerning, particularly for cigarettes (23%), 10 alcohol (10%) 11 and cannabis (7%). 12 Accordingly, efforts to prevent prenatal substance use are warranted, [13][14][15] particularly among people who are young, living on low income and coping with mental health challenges and are therefore at higher risk of prenatal substance use. 16 New research is needed on effective interventions to reduce prenatal substance use. 10,14,[17][18][19]