Yes, but don't overdo it. When caffeine enters your bloodstream, a small amount of it (usually less than 1 percent) ends up in your breast milk. The amount in your milk peaks a couple of hours after you consume it.
Since your newborn's body can't easily break down and get rid of caffeine, it may accumulate in his system. (At about 3 months, your baby will begin to process caffeine more efficiently, and over time it'll become easier for him to excrete it.)
咖啡因上限:
no more than 300 milligrams per day, or the amount in about 16 ounces of brewed coffee
裡面有食物同飲品咖啡因含量表:
https://www.babycenter.com/0_caffeine-and-the-nursing-mom_4488.bc