Alcohol! If she's breastfeeding she can drink. It's all perfectly safe.
This explains it well:
“Alcohol passes easily and quickly from the mother’s blood into her milk, and vice versa, so that the concentration in both liquids is the same.”
It’s easy to read this and make the quick assumption that if a mother is drinking 15 per cent Cabernet Sauvignon, her milk is of a similar strength, but of course, that’s not how it works. Gonzalez goes on:
“The legal driving limit in the UK is 0.08 per cent. If your alcohol level is higher than 0.15 per cent you are unmistakably drunk. If it goes above 0.55 per cent you simply drop dead. Therefore, it’s absolutely impossible for breastmilk to contain more than 0.55 per cent alcohol.”
However, as Gonzalez points out: “Alcohol-free beer can legally contain nearly double this level - up to 1 per cent alcohol. Consequently, even the breastmilk of a completely inebriated mother could be bottled and labelled ‘alcohol free’.”
orange juice naturally has up to 0.5% alcohol. your breast milk has the same amount of alcohol as your blood. three times the legal limit is 0.24%. that’s less than half the amount of naturally occurring alcohol in many orange juices.