Overview

• The systematic review found that prenatal cannabis use increases the risk of preterm birth by 52% and low birth weight by 75%.
• A 29% higher risk of infant death was identified in six of the reviewed studies, though certainty remains lower for this outcome.
• The study upgraded evidence certainty for adverse neonatal outcomes from low to moderate, reflecting more robust and consistent data.
• Mechanistic research shows that cannabis impairs placental function, reducing blood flow, oxygen delivery, and fetal lung development.
• Cannabis use during pregnancy has more than doubled since 2002, driven by recreational use and misperceptions of safety amid legalization.