The Association of Concomitant Maternal Marijuana Use on Health Outcomes for Opioid Exposed Newborns in Massachusetts, 2003-2009.

This population-based study showed that maternal opioid plus marijuana use during pregnancy was associated with increased odds of prematurity and low birth weight but lower odds of neonatal abstinence syndrome and prolonged hospitalization compared with opioid exposure without marijuana use. Further research should evaluate the biologic mechanisms responsible for these outcomes.