Even though herbal tea contains natural ingredients, that doesn't mean that they are necessarily safe, even though most women choose to drink it to help with annoying symptoms when pregnant or breastfeeding. The number of unwanted substances the herbal tea packs may contain can vary as well. They may contain some ingredients not listed on the packaging label that you could pass on to your baby during breastfeeding but check with your pediatrician or midwife first if you must take them.