Although pregnant women are urged to avoid alcohol completely, breastfeeding mothers are simply cautioned to consume it in small amounts.
Why only small amounts? Alcohol (beer, wine, liquor) passes easily into breast milk. Research shows that it can change the flavor of your milk, shorten your breastfeeding sessions, decrease your milk supply, and limit your baby’s weight gain.
Drinking small amounts (4 ounces of wine, 12 ounces of beer, or 1 ounce of liquor such as whiskey, rum, vodka, or gin) no more than once a week is thought to be safe. However, daily use of alcohol, even in small amounts, can affect your baby’s motor development and your ability to care for your baby.
To limit the effects of alcohol on you and your baby, have no more than one or two drinks a week, and wait at least two hours after you drink before breastfeeding.
The outdated suggestion to “pump and dump” was based on the belief that alcohol stays in the milk until it is removed from the breasts. We now know that this is false. The amount of alcohol in your milk depends on the amount in your blood. Even if you express and discard your milk, alcohol will re-accumulate in newly produced milk as long as there is alcohol in your blood. Alcohol is broken down (metabolized) and removed from your blood (and your milk) by the liver. It takes about two hours for the liver to break down the alcohol found in one drink.
It is important to remember that alcohol can make you sleep more soundly, so you should not sleep with your baby after drinking alcohol, due to the increased risk of suffocation and SIDS.