If you are breastfeeding, the safest approach is not to drink any alcohol.
Almost anything you eat or drink, including alcohol, passes to your breast milk.1 And the level of alcohol in breast milk will rise and fall along with the alcohol in your bloodstream.2
Your blood alcohol levels are at their highest between 30 and 60 minutes after drinking alcohol, or 60-90 minutes if you’ve been drinking with a meal.3 And it takes one to two hours for one unit of alcohol (80ml or just over half a small glass of wine, or half a pint of 4% strength beer) to clear from your bloodstream.4
Alcohol affects your baby’s sleep.5 One study found that babies who had alcohol via breast milk slept for 25% less time than those who didn’t.6
Alcohol also disrupts the hormone that controls the let-down of breast milk.7,8 Babies take around 20% less milk in the three to four hours after alcohol is consumed, and so will compensate by feeding more often.9,10,11
Although evidence suggests an occasional drink is unlikely to harm your breastfed baby,12,13 alcohol in breast milk may expose your baby to developmental delay, meaning it may develop more slowly (mentally or physically) than is normal for its age.14,15
If you are breastfeeding and you do choose to drink on occasion, the NHS advises that you:
Remember the level of alcohol in your breast milk will fall as the level of alcohol in your bloodstream falls – expressing milk after consuming alcohol will not clear it of alcohol more quickly than usual. However, if your breasts feel uncomfortable when you're not breast feeding for a few hours, you can 'pump and dump' – express milk and dispose of it – as often as your baby usually feeds.
[1] Giglia, R.C. (2010). Alcohol and lactation: An updated systematic review. Nutrition & Dietetics, 67(4), 237-243.
[3] Giglia, R. and Binns, C. (2006). Alcohol and lactation: a systematic review. Nutrition & Dietetics, 63(2), 103-116.
[5] Mennella, J.A. and Garcia-Gomez, P.L. (2001). Sleep disturbances after acute exposure to alcohol in mothers’ milk. Alcohol, 25(3), 153-158.
[6] Mennella, J. A. and Gerrish, C. J. (1998). Effects of exposure to alcohol in mother's milk on infant sleep. Pediatrics, 101, E2.
[7] Mennella, J.A., Pepino, M.Y. and Teff, K.L. (2005). Acute alcohol consumption disrupts the hormonal milieu of lactating women. The Journal of Clinical Endocrinology & Metabolism, 90(4), 1979-1985.
[8] Giglia, R.C. (2010). Alcohol and lactation: An updated systematic review. Nutrition & Dietetics, 67(4), 237-243.
[10] Mennella, J.A. and Beauchamp, G.K. (1991). The transfer of alcohol to human milk: Effects on flavor and the infant's behavior. New England Journal of Medicine, 325(14), 981-985.
[11] Mennella, J.A., 2001. Regulation of milk intake after exposure to alcohol in mothers' milk. Alcoholism: Clinical and Experimental Research, 25(4), 590-593.
[14] May, P.A., Hasken, J.M., Blankenship, J., Marais, A.S., Joubert, B., Cloete, M., de Vries, M.M., Barnard, R., Botha, I., Roux, S. and Doms, C. (2016). Breastfeeding and maternal alcohol use: Prevalence and effects on child outcomes and fetal alcohol spectrum disorders. Reproductive Toxicology, 63, 13-21.
[15] Gibson, L. and Porter, M. (2018). Drinking or smoking while breastfeeding and later cognition in children. Pediatrics, 142(2).
