Smoking Marijuana While Breastfeeding Could Make Your Baby High By Alexis Ty on June 09 2021 9:51 PM The researchers analyzed plasma from mothers, half of whom had gay sons; women with no sons; and men in order to find antibodies for the protein NLGN4Y, which is found in men. This protein helps neurons communicate with each other. Pregnant and breastfeeding mothers should abstain from using cannabis as much as possible, a doctor recently suggested after noting how marijuana might affect breastfed babies. The question on whether cannabis is safe to use during pregnancy or lactation is a pressing subject for some women, especially if they have been using the drug for medicinal purposes. According to cannabis clinician Dr. Leigh Vinocur, using cannabis while lactating could put the baby at risk of getting high from breast milk.