Can I drink tea when breastfeeding? You may still drink coffee or tea when breastfeeding. However, keep to 2 cups of either coffee or tea per day. Caffeine has been shown to pass through breast milk and may interfere with your baby's sleep. Although sleep deprivation in the first year often calls for a good dose of caffeine to get you through the day, sadly it's not ideal for breastfeeding – for you or your baby. It's best to avoid coffee, tea (except certain herbal teas), chocolate, cocoa, sugary sodas, and most iced teas, says Desi.