Whether caffeine affects your baby depends on your baby's age and health. If you have a healthy, full-term baby, small amounts of caffeine are thought to be safe. But there is evidence to suggest that large amounts of caffeine—more than 750 mg per day—may cause fussy, wakeful babies.
If you notice your baby becoming fussy, you may want to limit your intake of caffeine-containing drinks and foods such as coffee, tea, chocolate, and some carbonated beverages for 2-3 weeks to see if your baby's symptoms improve.
Check the ingredients listed on the package for caffeine content. The amount of caffeine in a cup of coffee or tea depends upon the equipment used for brewing and can range from 50-500 mg per 8 ounce serving.