While the consumption of alcohol is well known by the medical community as a potential hazard to a fetus, alcohol use during lactation is commonly a gray area for breastfeeding mothers. This article strives to clarify the extent to which a mother can safely use alcohol without adverse effects to her infant.
Alcohol transfers readily into human milk. Alcohol is not stored in milk; rather it equilibrates relative to the mother’s blood alcohol level. Levels of alcohol in milk peak at approximately 30 to 60 minutes following ingestion then decline rapidly if no more is ingested. An average adult metabolizes blood alcohol at the rate of about 15 to 20 mg/dL/hour. The dose of alcohol in milk is rather low (5-6% of the mother’s dose), but this is a function of how much the mother consumes.1
Older guidelines for determining the waiting period were rough estimates of the time required for elimination of alcohol. Body weight is a better predictor for how quickly a mother metabolizes alcohol. For an 82 kg woman, it takes about two hours per standard sized drink for there to be no alcohol left in the breastmilk. Higher body weights reduce this time; lower weights increase it.2
A new study indicates that non-alcoholic beverages that are designed to taste like alcohol (i.e., non-alcoholic beer) are harmless to infants.3
In terms of milk supply, new data now clearly demonstrate that alcohol interferes with the release or the effects of prolactin and oxytocin. Prolactin levels decrease significantly while the mother is intoxicated6 and the oxytocin response to breast stimulation can be completely blocked.5 Overall, the volume of milk expressed by mothers consuming modest amounts of alcohol was 9.3% less than on days when they consumed no alcohol.7 Furthermore, the alcohol-altered taste of the milk led to infants consuming 23% less milk from mothers who had recently had a drink.4
In essence, alcohol is not a contraindication to breastfeeding. However, successfully balancing the two requires moderation and careful planning.
1. Haastrup MB, Pottegard A, Damkier P. Alcohol and breastfeeding. Basic & clinical pharmacology & toxicology. Feb 2014;114(2):168-173.
2. Ho E, Collantes A, Kapur BM, Moretti M, Koren G. Alcohol and breast feeding: calculation of time to zero level in milk. Biology of the neonate. 2001;80(3):219-222.
3. Schneider C, Thierauf A, Kempf J, Auwarter V. Ethanol concentration in breastmilk after the consumption of non-alcoholic beer. Breastfeeding medicine : the official journal of the Academy of Breastfeeding Medicine. Jun 2013;8(3):291-293.
4. Mennella JA, Beauchamp GK. The transfer of alcohol to human milk. Effects on flavor and the infant's behavior. The New England journal of medicine. Oct 3 1991;325(14):981-985.
5. Coiro V, Alboni A, Gramellini D, et al. Inhibition by ethanol of the oxytocin response to breast stimulation in normal women and the role of endogenous opioids. Acta endocrinologica. Mar 1992;126(3):213-216.
6. Mennella JA, Pepino MY. Biphasic effects of moderate drinking on prolactin during lactation. Alcoholism, clinical and experimental research. Nov 2008;32(11):1899-1908.
7. Mennella JA. Short-term effects of maternal alcohol consumption on lactational performance. Alcoholism, clinical and experimental research. Oct 1998;22(7):1389-1392.