Breastfeeding and Drinking Alcohol

The majority of parents are aware that it’s safest not to drink any alcohol during pregnancy. But what about breastfeeding and drinking alcohol? Most experts agree that drinking small amounts of alcohol won’t hurt your baby, however opinions can vary over the amount of alcohol that is safe for a breastfeeding mother to drink. This article looks at the recommendations around breastfeeding and drinking alcohol and answers frequently asked questions.

Does alcohol get into breast milk?

Alcohol passes into breast milk reaching the same levels measured in a mother’s blood. However the amounts of alcohol moving into blood and breast milk are very low compared to the alcohol consumed1. Dr Jack Newman, a Canadian paediatrician explains:

Depending on the jurisdiction, you are considered too drunk to drive with more than 0.05% to 0.1% alcohol in your blood. Alcohol behaves differently from other drugs. The concentration of alcohol in blood and breastmilk is about the same. So, if the mother has 0.06% alcohol in her blood, she will have 0.06% alcohol in her milk—one-tenth that of de-alcoholized beer! This is not a concentration of alcohol that is going to make the baby sick or cause brain damage (as some have suggested).

Alcohol levels peak in breast milk about 30-60 minutes after drinking or after 30-90 minutes if taken with food2. And the concentration of alcohol gradually falls if the mother doesn’t have another drink. A couple of hours after having a single drink (i.e. one unit of alcohol), the alcohol will have mostly left the mother’s breast milk (and her blood) because alcohol is not stored in the breast. One unit of alcohol is approximately a single (25ml) measure of spirits, half a pint of beer or half a standard (175ml) glass of wine, although it depends on the strength of the drink—see this Drinkaware’s Alcoholic unit calculator or Alcohol Change UK’s Unit calculator. The more drinks a mother has, the longer it takes for her body to clear the alcohol (see below).

What happens if baby drinks breast milk with alcohol?

Drinking small amounts of alcohol occasionally won’t affect the breastfed baby. 34.

However drinking excess alcohol may affect:

Baby’s sleep and growth

Drinking regularly or heavily while breastfeeding may lead to drowsiness, deep sleep, weakness and decreased growth for your baby.5

Problems with milk let-down

Studies have shown that excess alcohol can affect the hormones that control breast milk production with the potential to reduce a milk supply and affect the let-down (when milk releases from the breast)67. For this reason drinking alcohol has not been shown to increase a mother’s breast milk supply despite the fact that drinking beer was historically thought to be very good for helping a mothers’ milk supply. For further information see Beer and Breastfeeding.

Milk intake

The Womanly Art of Breastfeeding explains that babies seem to take less milk when there is alcohol in it which could affect a baby’s growth if a mother drinks a lot:

…babies don’t metabolise alcohol nearly as well as adults do, and when there’s alcohol in the milk they seem to take less milk than they would otherwise. Combine that with the slowed milk release that can result from alcohol, and your supply and your baby’s growth can be compromised if you drink substantial amounts regularly. A beer or a glass of wine a couple of times a week is unlikely to matter, and the effects decrease as your baby gets older.

What you can do

If you want to minimise the alcohol your baby gets, try breastfeeding right before you have a drink—your milk will be alcohol-free again within two or three hours.

How much alcohol can affect a breastfed baby?

Pharmacist Wendy Jones from the Breastfeeding Network says that a mother’s alcohol blood levels would need to reach 300mg/100ml to make a baby sleepy:

maternal blood levels have to reach 300mg/100ml before mild sedation is reached in the baby (this compares with a level of 80mg/100ml needed to fail the police breath test in England, Wales and N. Ireland; 50mg/100ml Scotland.

In terms of units of alcohol drunk, equates 200–300mg/100ml blood level to 15-20 units of alcohol (7-10 pints of beer) noting that after drinking this amount most people would have passed out.8

Alcohol Change Uk and UK’s National Health Service recommend drinking no more than 14 units per week spread over three or more days as general guidance for everyone.9 10

How much alcohol affects the let-down?

Breastfeeding and medications author Thomas Hale says that to affect a mother’s let-down, 1.5 to 1.9 g/kg alcohol will need to be consumed 11. According to Lundgaard et al 12 alcohol consumption of 1.5 g/kg is “binge level” and NHS describes binge drinking as more than 6 units of alcohol in one drinking session13. See the next section for more on binge drinking and breastfeeding.

Drinking alcohol and caring for your baby

Drinking alcohol can affect a mother’s capacity to look after her baby, particularly enough alcohol to make her feel disorientated or be sick. The Breastfeeding Network and the UK’s NHS remind mothers of the dangers of drinking alcohol while in charge of a baby, irrespective of feeding method:

It is vital that mothers who have been drinking alcohol should never let themselves be in a situation where they might fall asleep with the baby; on a bed, chair or settee (this would also apply to other carers who have been drinking alcohol).  The place of sleep is a bigger risk than the fact that the mother has been drinking unless her consumption has been very high.

Drinking alcohol reduces the ability of the mother to be aware of her baby’s needs, whether she is breastfeeding or not. It is safest to ask someone else to care for the baby.

Binge drinking, where you have more than 6 units of alcohol in 1 session, may make you less aware of your baby’s needs.

If you do binge drink, your baby should be cared for by an adult who has not had any alcohol.
You may want to express for comfort and to maintain your milk supply.

Do I need to “pump and dump”?

There is no need to pump and throw away your breast milk after having an alcoholic drink—unless you are engorged and need to express for comfort. The alcohol will naturally leave the milk in your breasts of its own accord and pumping won’t hurry the process. Any milk you express during the waiting period will still contain alcohol (the alcohol won’t disappear from the milk as it does in the breast).

As alcohol leaves the bloodstream, it leaves the breast milk. Since alcohol is not “trapped” in breast milk (it returns to the bloodstream as mother’s blood alcohol level declines), pumping and dumping will not remove it. Pumping and dumping, drinking a lot of water, resting, or drinking coffee will not speed up the rate of the elimination of alcohol from your body.

How long does it take for alcohol to leave my breast milk?

Exactly how quickly the alcohol will clear from your breast milk depends on how many units of alcohol you have drunk, your body weight and whether you have eaten food with the alcohol. The Academy of Breastfeeding Medicine 14 refers mothers to the Motherisk Program’s table which gives estimated time intervals for alcohol to clear from breast milk depending on units consumed and body weight. The less you have drunk and heavier you are, the quicker your body can metabolise the alcohol. Examples from the table:

  • A nine stone woman (125lb/57kg) is estimated to metabolise one unit of alcohol from her breast milk in 2.5 hours and four units in 10 hours.
  • A twelve stone woman (170lb/77kg) is estimated to metabolise one unit of alcohol from her breast milk in about two hours and four units in just over eight hours.

How can I reduce the effects of alcohol on my baby?

To minimise the alcohol a baby gets, a mother could avoid breastfeeding for two or three hours after she has had a drink.15 Some experts advocate waiting two hours before breastfeeding for every unit of alcohol consumed16 but others feel this may be overly cautious as the actual amounts of alcohol moving into breast milk are very low17. Denise Fisher, IBCLC makes the following recommendations to reduce a baby’s exposure to alcohol:

  • minimising alcohol exposure to the infant for at least the first 3 months of life
  • choosing low alcohol [or non alcoholic!]drinks
  • eating before and while drinking
  • avoiding breastfeeding for 2 to 3 hours after drinking
  • storing alcohol-free breast milk for use after moderate or heavy drinking

There is no requirement to pump and dump (see above) however if your breasts become full during the waiting period for the alcohol to clear, hand express or use a breast pump.


Small amounts of alcohol move into breast milk when a breastfeeding mother has an alcoholic beverage. The concentration of alcohol peaks in breast milk about 30-60 minutes after the drink is consumed and then the levels gradually fall if the mother doesn’t have another drink. A couple of hours after having one unit of alcohol, the alcohol will have mostly left your breast milk. Drinking small amounts of alcohol occasionally won’t affect your baby, however drinking regularly or heavily may affect your milk supply and/or your let-down reflex, make your baby sleepy or affect their growth.

*Book extracts reproduced by permission from Pinter & Martin.