One standard glass of wine (5 ounces at 12% alcohol) is generally considered compatible with breastfeeding, as long as you wait at least 2 hours before nursing. The American College of Obstetricians and Gynecologists advises that drinking more than two drinks per day on a regular basis may cause drowsiness, weakness, and abnormal weight gain in your baby.
What Counts as One Glass
A “standard drink” of wine is 5 ounces at 12% alcohol. That’s smaller than most people expect. A typical restaurant pour can run 6 to 8 ounces, and many wines, especially reds, clock in at 13 to 15% alcohol. If you’re pouring at home, measuring once with a kitchen scale or measuring cup gives you a realistic sense of what 5 ounces actually looks like in your usual glass. A large wine glass filled to a comfortable level often holds closer to two standard drinks.
How Alcohol Gets Into Breast Milk
The alcohol level in breast milk is essentially the same as the alcohol level in your bloodstream. After you finish a glass of wine, alcohol is absorbed and peaks in both your blood and your milk within 30 to 60 minutes. From there, it moves freely back and forth between your blood and milk, staying in balance. As your body metabolizes the alcohol and your blood alcohol drops, the concentration in your milk drops at the same rate.
This is why “pumping and dumping” doesn’t speed anything up. Expressing milk removes the milk that’s currently in your breasts, but new milk your body produces will still reflect whatever alcohol is in your blood at that moment. The only thing that clears alcohol from your milk is time.
How Long to Wait Before Nursing
ACOG recommends waiting at least 2 hours after a single drink before breastfeeding. That window gives your body enough time to metabolize most of the alcohol from one standard glass of wine. If you have a second glass, you’ll need to add more time, roughly 2 hours per drink. Your body weight matters too: a smaller person metabolizes alcohol more slowly than a larger one, so the same glass of wine stays in your system longer.
If your baby needs to eat during that window, using previously expressed milk is the simplest workaround. Some parents plan their drink right after a feeding to maximize the gap before the next one, especially with younger babies who nurse frequently.
What Alcohol Does to Your Baby’s Sleep and Feeding
Even one or two drinks can have measurable effects. Research compiled by La Leche League International shows that nursing after one or two drinks can decrease the infant’s milk intake by 20 to 23%. Babies tend to nurse more frequently but take in less milk per session, likely because alcohol interferes with the let-down reflex.
Sleep is affected too. Infants exposed to alcohol through breast milk spend significantly less time in both active sleep and total sleep. REM sleep, the phase that’s important for brain development, is disrupted in the 3 hours following exposure. After that initial disruption, babies often show increased REM sleep in the hours that follow, as if compensating, but the overall pattern is fragmented. Parents frequently notice more agitation and wakefulness during these periods.
What “Regular Drinking” Can Do
An occasional single glass of wine is treated differently from a daily habit in the medical literature. ACOG specifically warns that more than two drinks per day on a regular basis may be harmful and can cause drowsiness, weakness, and abnormal weight gain in the baby. The concern here is cumulative exposure. A developing infant’s liver metabolizes alcohol far more slowly than an adult’s, so repeated exposure creates a higher overall burden even if each individual dose is small.
Practical Planning
If you want to enjoy a glass of wine occasionally, a few strategies make the timing easier:
- Nurse or pump first. Feed your baby right before you drink so you have the longest possible window before the next session.
- Keep expressed milk on hand. If your baby gets hungry before the 2-hour mark, a bottle of previously pumped milk bridges the gap.
- Measure your pour. Knowing what 5 ounces looks like in your glass prevents accidentally doubling your intake.
- Eat beforehand. Food slows alcohol absorption, which lowers your peak blood alcohol level and reduces the peak concentration in your milk.
There’s no need to test your milk with alcohol detection strips. These products can detect trace amounts of alcohol but don’t tell you whether the level is meaningful. Since breast milk alcohol tracks your blood alcohol, the most reliable gauge is time: if you feel completely sober and at least 2 hours have passed since your last drink, your milk has cleared as well.