The short answer is yes, you can drink coffee and other caffeinated drinks while you're breastfeeding.
Let's dig a little deeper to help you make an informed decision about how much caffeine you drink, and how you might experiment with intake and timing.
The basics
All the existing research shows that small amounts of caffeine gets into breast milk, but it's not necessary to cut out coffee altogether.
About 1% of the caffeine you consume ends up in your breastmilk, reaching a peak about 60 minutes after you consumed it and petering off from there.
One or two cups of coffee a day is likely to have little or no effect on your baby. Newborns can be more sensitive (they can take up to 160 hours to process caffeine), than say 6-month old babies (they can process caffeine in about 2-3 hours).
To minimise the caffeine your baby is exposed to, you can time your intake so that you feed 2 hours or more after you consume coffee.
The conservative guidelines all state that 300mg a day should have practically no effect on your baby.
So what does 300mg look like?
So how much caffeine is in things?
50g of milk chocolate = <25gramsA can of cola = 40mg
A cup of tea = 50mg
A cup of instant coffee = 75mg
An energy drink = 80mg
A cup of espresso coffee = 58 to 100mg