Brain and behavior correlates of prenatal cannabis exposure

Cannabis use during pregnancy has increased substantially, in conjunction with widespread decriminalization/legalization, changing public perceptions about harm, and evidence of cannabis's antiemetic properties. Prior outcomes research on prenatal cannabis exposure is narrow in scope, as these older studies included research participants with polysubstance use (e.g., tobacco, alcohol, illicit drugs). In addition, prior research also likely underestimated potential risks specific to cannabis use during pregnancy because modern strains are 10x more potent than they were 40 years ago. We propose to study neurodevelopment in infants exposed in utero to cannabis using state-of-the-art MRI and behavioral measures. Maternal cannabis use will be measured prospectively using weekly reports validated with labels and urine-based assays. By focusing on infancy, we aim to characterize cannabis-induced brain changes at a time when environmental effects are minimized and are less influential than at older. In addition, we will test the hypothesis that prenatal cannabis exposure is more detrimental to male than females. To test our hypotheses, we will recruit 200 pregnant people (where the mother uses cannabis, but not other drugs, tobacco, or alcohol) and 170 pregnant control participants matched on education level. Infants will receive a neonatal neurobehavioral exam and multi-modal imaging (functional magnetic resonance imaging, diffusion tensor imaging, and structural MRI) under natural sleep at 2-4 weeks-of-age and extensive neuropsychological follow-up assessments at 6 and 18 months. This program of research aims to clarify potential health risks, enabling pregnant people to make better-informed choices surrounding cannabis use during pregnancy.