How Much Alcohol Passes Through Breast Milk?

By Sharon Secor
A nursing mother can safely drink an occasional glass of wine with dinner, states.
A nursing mother can safely drink an occasional glass of wine with dinner, states.

Like many other substances, alcohol passes through breast milk, leading many breastfeeding mothers to worry about whether they should have that glass of wine with dinner. A single glass of wine with dinner is unlikely to harm a healthy infant, according to Approximately 2 percent of the alcohol a mother drinks ends up in her breast milk, according to the National Institute on Alcohol Abuse and Alcoholism.

Culture, Tradition and Old-Time Advice

For hundreds of years, nursing mothers have often been told that alcohol can help with the let-down reflex and the flow of their milk. Alcohol was said to be useful in helping mother and baby relax. Doctors used to suggest it to mothers and, in some parts of the world, it is still common practice. However, modern research reveals a different set of facts. Instead of increasing the flow of breast milk as once believed, drinking alcohol actually decreases breast milk production by about 20 percent for a few hours, according to the National Institute on Alcohol Abuse and Alcoholism.

Effects of Alcohol on Breastfed Baby

Regular exposure through breast milk to alcohol can affect an infant's gross motor development, as well as disrupt sleeping and eating cycles, according to the National Institute on Alcohol Abuse and Alcoholism. Research suggests that tasting alcohol in breast milk, along with the warmth and comfort of nursing, can set a taste for it. Citing her work with Gary K. Beauchamp in an article for the National Institute on Alcohol Abuse and Alcoholism, Dr. Julie A. Mennella noted that infants who were exposed regularly to alcohol reacted differently to the smell of alcohol than infants who had not been exposed. "Infants who had more exposure to alcohol demonstrated more mouthing of the alcohol-scented toy, but not of the other toys, than did infants with less alcohol exposure," Mennella states. The other toys were vanilla-scented or unscented. Mothers who typically drink three or more alcoholic beverages a day may notice that their babies reach developmental milestones at a slower rate, warns the Australian Breastfeeding Association.

Factors Affecting Breast Milk Alcohol Content

How much alcohol is in the breast milk depends upon how much the mother drinks, how fast she drinks it, her weight, and whether she is eating while drinking, according to the Australian Breastfeeding Association. The higher the mother's alcohol blood content, the higher the alcohol content of her breast milk will be. If you are a breastfeeding mother, it is best to "allow at least two hours per drink or two before your next breastfeeding or pumping session," according to

Plan for Safety

With one drink defined as 12 ounces of beer, 5 ounces of wine or 1.5 ounces of liquor, it takes about 5 hours for two drinks to leave the system of a woman weighing 120 pounds, according to the Sonoma County Perinatal Alcohol and Other Drug Action Team. For a woman of that weight, it takes three drinks about 7.5 hours to clear. "Breastfeeding mothers should avoid the use of alcoholic beverages, because alcohol is concentrated in breast milk and its use can inhibit milk production. An occasional celebratory single, small alcoholic drink is acceptable, but breastfeeding should be avoided for 2 hours after the drink," states the American Academy of Pediatrics.

About the Author

Sharon Secor began writing professionally in 1999, while attending Empire State University. Secor specializes primarily in personal finance and economics, and writes on a broad range of subjects. She is published in numerous online and print publications, including Freedom's Phoenix, the ObscentiyCrimes and the American Chronicle.