Updated April 28, 2014.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Drinking alcohol is considered normal, and although there has been a strong message that alcohol during pregnancy causes fetal alcohol spectrum disorder (FASD) and should be avoided, the message about alcohol use during breastfeeding has been less clear.

Traditionally, women were told that alcohol is a galactogogue -- a substance that promotes the production of breastmilk -- although research shows that in fact it has the opposite effect.

Yet the perception that alcohol is not a problem once the baby is born has been persistent, so parents often make poorly informed decisions about drinking and breastfeeding.

Here's what the research tells us.

Women's Drinking Patterns and Opinions About Alcohol Vary

One of the difficulties in advising women about drinking is that there are huge differences between women's drinking patterns, ability to regulate and control their drinking, and perceptions about how much is too much alcohol. While there is some variation between women based on body weight and speed of drinking, even without breastfeeding, most women shouldn't have more than two standard drinks a day. Many women drink much more than this, and don't even realize that once they go over three drinks, they are into binge drinking territory.

• Read more about Blood Alcohol Content for Women

Tip: Don't go over a single standard drink in a day -- on an occasional basis -- if you are breastfeeding, and if you have any difficulty stopping at one, don't drink at all until you have weaned your baby.

Breastfeeding and Alcohol

If you drink alcohol while breastfeeding, it will be transmitted to your baby in your breastmilk. Newborn babies detoxify alcohol in their bodies at about half the rate that adults do, and the liver does not mature until the baby is about three months old. Therefore, alcohol consumed through your breastmilk will have a much more powerful effect on your baby than it would on you or me.

Tip: If you are planning on drinking, breastfeed beforehand, and if possible, express and store some alcohol-free breastmilk to feed your baby during the 3-hour period after finishing drinking.

What Will Alcohol Do to My Baby if I Do Drink and Breastfeed?

Much more is known about the harmful effects on babies whose mothers drink during pregnancy than on the children of mothers who drink and breastfeed, but there are some risks we know about from research:

• Risk of SIDS -- alcohol causes drowsiness, and can therefore increase the risk of your baby dying of SIDS.

• Effects on the Brain and Nervous System -- in high doses, alcohol-contaminated breastmilk can cause a disease in babies called Pseudo-Cushing Syndrome, a pattern of abnormal growth, weight gain, and appearance.

• Delayed Motor Development -- as little as one drink a day can cause your baby to have significantly lower motor development than babies who are not exposed to alcohol.

• Mental Functioning -- severe damage to mental functioning is known to result from prenatal exposure to alcohol. Less is known about exposure through breastfeeding only, although your baby's brain is still developing in infancy.

Tip: Early exposure to alcohol may be harmful to your baby. If you know you have alcohol in your system, avoid breastfeeding.

The Bottom Line

Drinking is part of most adults' lifestyles, and many women resist giving up pleasures they enjoyed before becoming parents. But the risk of harming your baby outweighs the benefit of breastfeeding if there is alcohol in your breastmilk. The best approach is to avoid alcohol completely until you have weaned your baby, but if you choose to drink and breastfeed, be careful to only expose your baby to alcohol-free breastmilk by having only one drink at a time, and waiting three hours after finishing your drink to breastfeed again. It can help to express and store your breastmilk first thing in the morning, so your baby has a supply of "clean" milk.

<sub>Sources

American Academy of Pediatrics "Policy Statement: Breastfeeding and the Use of Human Milk." Pediatrics 129:e827-e841.

Academy of Breastfeeding Medicine Protocol Committee. "ABM Clinical Protocol #21: Guidelines for Breastfeeding and the Drug-Dependent Woman." Breastfeeding Medicine 4:225-228. 2009.

Berger, M.D., M.P.H., L., "When Should One Discourage Breastfeeding." Pediatrics 67:300-302. 1982.

Cook, P., Petersen, R. & Moore, D. Alcohol, Tobacco, and Other Drugs May Harm the Unborn. DHHA (ADM) Report No. 92-1711. 1990.

Hartney, E., Orford, J., Dalton, S., Ferrins-Brown, M., Kerr, C., & Maslin, J. "Untreated heavy drinkers: a qualitative and quantitative study of dependence and readiness to change." Addiction Research and Theory 11:317-337. 2003.

Liston, J. "Breastfeeding and the Use of Recreational Drugs -- Alcohol, Caffeine, Nicotine and Marijuana." Breastfeeding Review 6:27-30. 1998.

Koren, G. "Drinking alcohol while breastfeeding. Will it harm my baby?" Can Fam Physician 48:39-41. 2002.

Wilton, J. "Breastfeeding and the Chemically Dependent Woman." NAACOG's Clinical Issues in Perinatal and Women's Health Nursing 3:667-7. 1992.</sub>