A report from the American Academy of Pediatrics (AAP) published in the journal Pediatrics cautions pregnant women and nursing mothers to avoid marijuana use due to possible adverse developmental effects to their baby. In a study reviewed for the report, short-term exposure to CBD was found to increase the permeability of the placental barrier, potentially placing the fetus at risk from certain substances.
Laboratory evidence indicated that cannabidiol may reduce THC clearance, increasing plasma concentrations which may raise THC availability to receptors and enhance its effect in a dose-dependent manner. In vitro, cannabidiol inhibited receptors affecting the activity of voltage-dependent sodium and potassium channels, which may affect neural activity. A small clinical trial reported that CBD partially inhibited the CYP2C-catalyzed hydroxylation of THC to 11-OH-THC.