Abstract: Background: Cardiovascular anomalies are the largest group of congenital anomalies and the major cause of death in young children, with various data linking rising atrial septal defect incidence (ASDI) with prenatal cannabis exposure. Objectives / Hypotheses: Is cannabis associated with ASDI in USA? Is this relationship causal?
Results: ASDI rose nationally three-fold from 27.4 to 82.8 / 10,000 births 1991–2014 during a period when tobacco and alcohol abuse were falling but cannabis was rising.