The amount of alcohol in your blood is the same as the amount of alcohol in your breastmilk.
It is generally safe to enjoy the occasional glass of alcohol but there are a few factors to take into consideration, including your weight, your food intake, alcohol strength, volume consumed, timing of breastfeeds and the age of your baby. A newborn’s liver is more immature making it difficult to breakdown alcohol whereas an older baby has the ability to metabolize the alcohol much quicker.
Alcohol has also been reported to reduce milk volume and inhibit oxytocin the hormone necessary to create milk let-downs.
Alcohol will appear in your blood 30-60 minutes after you begin drinking, so if you do wish to enjoy an alcoholic drink, it is safest to do it immediately after a feed. There is no need to pump and throw away your breastmilk as this does not speed up the elimination of alcohol from the milk.
REMEMBER: The only thing that will reduce the amount of alcohol in your breastmilk is time. The length of time it takes for your blood alcohol levels to drop down is the same time it will take for your milk alcohol levels to drop.
If you plan to have a drink, the Australian Breastfeeding Association (ABA) has a great app, Feed Safe that will time how long you need to wait to breastfeed after you start an alcoholic drink.