What Research Says About the Safety of Drinking While Breastfeeding

Drinking alcohol is considered a normal activity, 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. So new Moms often wonder whether alcohol and breastfeeding can be combined.

Traditionally, women were told that alcohol is a galactagogue -- a substance that promotes the production of breast milk -- 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.

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's blood-alcohol content 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.

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.

If you drink alcohol while breastfeeding, it will be transmitted to your baby in your breastmilk. Very little is known about the direct effects of drinking on breastfeeding; a 2017 study showed that over half of Australian women who breastfeed drink at low levels, and use strategies, such as timing when they drink and breastfeed, which does not seem to be harmful to babies at 12 months. However, the effects on the baby after 12 months have not been assessed.

Some breastfeeding advocates believe that the benefits of breastfeeding outweigh the risks of drinking and breastfeeding and that women should focus on combining breastfeeding and alcohol safely, rather than aiming for abstinence, which could be unrealistic.

Here are some of the guidelines they recommend:

• Not drinking alcohol is the safest option.
• Women should avoid alcohol in the first month after delivery until breastfeeding is well established.

After that:

• Alcohol intake should be limited to no more than two standard drinks a day
• Women should avoid drinking immediately before breastfeeding
• Women who wish to drink alcohol could consider expressing milk.

However, it is worth bearing in mind that most people who pour their own drinks vastly underestimate how much alcohol they consume; one standard drink is probably a lot less than you would expect. 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.

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 pump and store your breastmilk first thing in the morning, so your baby has a supply of "clean" milk.