evidence: Lactation: Cannabinoids are excreted in human milk and may be absorbed by the nursing babyReference 1385Reference 1386. Because of potential risks to the child, nursing mothers should not use cannabis. [...] Evidence suggests that cannabinoids accumulate in the breast milk of mothers who smoke cannabis and are transferred to newborns through breastfeedingReference 1385Reference 1515. Indeed, the THC concentration of breast milk in humans may be up to eight-fold higher than that found in maternal bloodReference 1385Reference 1488. In a case-control studyReference 1516, exposure to cannabis from the mother's milk during the first month post-partum appeared to be associated with a decrease in infant motor development at one year of age. [...] Perez-Reyes M, Wall ME. Presence of delta9-tetrahydrocannabinol in human milk. N Engl J Med 1982 09/23;307(0028-4793; 13):819-20.