We do not yet know. Chemicals from marihuana can be passed to your baby through breast milk. THC is stored in fat and is slowly released over time, meaning that your baby could still be exposed even after you stop using marihuana. However, data on the effects of marihuana exposure to the infant or baby through breastfeeding are limited and conflicting. To limit potential risk to the infant, breastfeeding mothers should reduce or avoid marihuana use.