Hey there, it depends on how. Baby reacts to it , bc every baby is different. I also read that caffeine can affect quality of breastmilk. For some babies caffeine can make a baby irritable and fussy...
However for me and my cousin we drink lots of caffeine and our babies are smart aNd healthy ! I usually have two cups of Starbucks iced coffee unsweetened for my daily does of caffeine. As long as u don't make espresso a habit you should be fine.

Probably wouldn't. It's better to avoid it