Alcohol and Breastfeeding: What Research Says

For many new mothers, the question of whether it’s safe to consume alcohol while breastfeeding remains a source of confusion and anxiety. After nine months of abstaining during pregnancy, some women wonder if an occasional glass of wine or beer is acceptable while nursing. With conflicting advice from various sources and persistent myths about alcohol and milk supply, it’s crucial to examine what the latest research actually tells us about alcohol consumption during lactation.

This comprehensive review examines the most current scientific evidence on alcohol and breastfeeding, including how alcohol transfers to breast milk, its effects on infant development, and evidence-based guidelines for nursing mothers who choose to drink.

The Science Behind Alcohol Transfer to Breast Milk

How Alcohol Moves from Mother to Baby

Alcohol transfers into breastmilk at the same rate that it transfers to the mother’s blood, with milk alcohol levels closely paralleling blood alcohol levels. This means that when a mother’s blood alcohol level rises, so does the alcohol content in her breast milk.

Studies have shown that milk alcohol levels typically peak between 30 to 60 minutes after consuming an alcoholic beverage, with the highest levels occurring at the first measurement at 60 minutes after ingestion when consumed with food. The timing can vary based on several factors:

Food consumption: Drinking with meals slows alcohol absorption
Body weight: Heavier individuals metabolize alcohol more quickly
Individual metabolism: Varies significantly between people
Amount consumed: More alcohol takes longer to clear

The Numbers: How Much Alcohol Reaches Your Baby?

Research provides reassuring data about the actual amount of alcohol that reaches nursing infants. The amount of alcohol presented to nursing infants through breast milk is approximately 5-6% of the weight-adjusted maternal dose. To put this in perspective, even in theoretical cases of binge drinking, the exposure remains relatively limited.

According to the CDC, alcohol can be generally detected in breast milk for about 2 to 3 hours per drink after it is consumed. The detection timeline increases with consumption:

1 drink: 2-3 hours
2 drinks: 4-5 hours
3 drinks: 6-8 hours

Effects on Infant Development and Health

Immediate Effects on Nursing Behavior

One of the most interesting findings from research is how alcohol affects the nursing relationship itself. Studies have found that the ingestion of alcohol by a lactating woman altered the odor of her milk and that exposure to a small amount of alcohol in the mother’s milk had immediate effects on the behavior of the infant.

Multiple studies have documented that:

Infants consume less milk when alcohol is present
Babies nurse more frequently when their mother has consumed alcohol, but they seem to take less milk than they would otherwise in the 3-4 hours after an alcoholic beverage is consumed
Compensatory increases in milk intake occur 8-16 hours after exposure

Long-term Developmental Concerns

The long-term effects of alcohol exposure through breast milk are an area of ongoing research with some concerning findings from both human and animal studies:

Brain Development

Recent 2023 research using mouse models has revealed potential impacts on brain development. Young mice that were exposed to alcohol during early development show smaller body and brain growth, as well as decreased cortical lengths — a measure of brain size. These findings suggest that regular alcohol exposure through breast milk could potentially affect neural development.

In mouse studies, brain weights were reduced in both ages for males, and at postnatal day 20 for females; however, female brain weights recovered to control levels by day 30, indicating potential sex-specific differences in how alcohol exposure affects development.

Growth and Weight

The reduced body weights observed in mice exposed to alcohol through nursing are reflected in human studies where children exposed to ethanol through contaminated breast milk have lower body weights and growth trajectories. This may be explained by alcohol’s interference with nutrient absorption in the developing digestive system.

Behavioral Development

Animal studies have raised concerns about behavioral changes. Results of behavioral tests suggest that mice exposed to alcohol through lactation engage in higher risk-taking behavior, show abnormal stress regulation, and exhibit increased hyperactivity. However, it’s important to note that these studies involved regular, sustained exposure rather than occasional maternal drinking.

Infant Metabolism: A Critical Factor

Understanding how infants process alcohol is crucial for assessing risk. Newborns metabolize alcohol at approximately half the rate of adults. The elimination rate of ethanol in very young infants has been calculated to be in a range from 17.1 to 21.2 mg/dL/hr, which is slower than in older children and may reflect decreased alcohol dehydrogenase levels.

This slower metabolism means that:

Alcohol remains in an infant’s system longer than in adults
Very young infants (under 3 months) are particularly vulnerable
The infant’s immature liver cannot process alcohol efficiently

Impact on Milk Supply and Let-down

The Beer Myth Debunked

One of the most persistent myths about alcohol and breastfeeding is that beer increases milk supply. While animal studies have revealed that young animals form memories based on sensory experiences during nursing, and the folklore of many cultures encourages lactating women to drink alcohol to optimize breast milk production, the scientific evidence tells a different story.

More than moderate levels of alcohol consumption can interfere with the milk ejection reflex (letdown), and over time, excessive alcohol consumption could lead to shortened breastfeeding duration due to decreased milk production. Alcohol acts as an oxytocin inhibitor, which can:

Temporarily decrease milk yield
Disrupt the let-down reflex
Lead to decreased milk supply with regular heavy use

Hormonal Effects

Alcohol can decrease milk production, with 5 drinks or more decreasing milk letdown and disrupting nursing until maternal alcohol levels decrease. Women with a family history of alcoholism may have additional vulnerabilities, showing a blunted prolactin response following breast stimulation.

The “Pump and Dump” Controversy

Understanding the Science

“Pumping and dumping” refers to expressing breast milk after drinking and discarding it. However, research shows this practice is largely based on misunderstanding. The amount of alcohol that gets into the milk is relatively small, and alcohol passes through your breastmilk at the same rate as it passes through your bloodstream.

Expressing or pumping then discarding milk after drinking alcohol does not reduce the amount of alcohol in the mother’s milk more quickly, as the alcohol level in breast milk is essentially the same as the alcohol level in a mother’s bloodstream. As blood alcohol levels fall naturally over time, milk alcohol levels decrease simultaneously.

When Pumping Might Be Helpful

While pumping and dumping doesn’t remove alcohol from your system faster, there are situations where pumping (though not necessarily dumping) makes sense:

To maintain milk supply if you miss a feeding
To relieve engorgement while waiting for alcohol to clear
To have expressed milk available for feeding while alcohol is in your system

Evidence-Based Guidelines for Nursing Mothers

Official Recommendations

Current guidelines from major health organizations provide a framework for mothers who choose to drink:

The CDC states that not drinking alcohol is the safest option for breastfeeding mothers. However, moderate alcohol consumption, meaning up to one drink per day, is not known to be harmful to the infant.

Special recommendations aimed at lactating women are not warranted. Instead, lactating women should simply follow standard recommendations on alcohol consumption. The key is moderation and timing.

Practical Strategies for Occasional Drinking

For mothers who choose to have an occasional drink, research supports these evidence-based strategies:

Time your drink carefully: With casual alcohol use (such as 1 glass of wine or beer) it is best to wait 2 to 2.5 hours per drink before nursing
Feed first, then drink: Nurse your baby immediately before consuming alcohol to maximize the time for alcohol clearance
Know your limits: The general rule of thumb is that if you would be legally safe to drive after drinking alcohol, then your breastmilk is safe for your infant
Plan ahead: Have previously expressed milk available if needed
Consider your baby’s age: Very young infants (under 3 months) are more vulnerable due to their immature metabolism

Need an answer right now? Try our free alcohol timer for breastfeeding mothers.

When to Avoid Alcohol Completely

Certain situations call for complete abstinence:

If you have a history of alcohol abuse or addiction
When caring for premature or medically fragile infants
If you’re taking medications that interact with alcohol
During the early weeks when establishing milk supply

Latest Research Updates: 2025 Findings

Developmental Impacts

Recent 2025 research from the National Institutes of Health indicates that heavy maternal use may cause excessive sedation, fluid retention, and hormone imbalances in breastfed infants, and greater or riskier alcohol consumption by nursing mothers may affect their children’s academic performance negatively in school.

Mouse Model Studies

A groundbreaking 2023 study published in Frontiers in Neuroscience provided new insights using a mouse model of lactational ethanol exposure. Researchers found that approximately 36% of breastfeeding mothers in the United States consume alcohol, while in Canada and Australia, the numbers are 20% and 60%, respectively. This research highlighted the need for clearer guidelines and better education for nursing mothers.

Long-term Outcomes

A recent analysis from The Growing Up in Australia Study found that while prenatal alcohol and tobacco intake have been associated with negative outcomes in children, maternal alcohol consumption and tobacco smoking while breastfeeding were not associated with developmental health outcomes at ages 6-7 years and 10-11 years when consumed in moderation.

The Role of Individual Variation

Maternal Factors

Not all mothers metabolize alcohol at the same rate. Metabolic capacity among pregnant women varies eightfold (from 0.0025 to 0.02 g dl−1 h−1), which may help explain how similar amounts of ethanol consumption during pregnancy results in widely varying phenotypic presentations. This variation likely extends to the lactation period as well.

Infant Factors

Individual infants also vary in their ability to process alcohol based on:

Gestational age at birth
Current age
Overall health status
Genetic factors affecting alcohol metabolism

Making Informed Decisions

Risk vs. Benefit Analysis

For many mothers, the decision about alcohol consumption while breastfeeding involves weighing multiple factors:

Benefits of continued breastfeeding:

Optimal nutrition for infant
Immune system support
Bonding and emotional benefits
Long-term health advantages

Risks of alcohol consumption:

Potential developmental effects with heavy use
Temporary reduction in milk intake
Possible sleep disruption in infant
Risk of impaired caregiving if intoxicated

Communication with Healthcare Providers

Open dialogue with healthcare providers is essential. Mothers should:

Discuss their alcohol consumption honestly
Ask about interactions with any medications
Seek guidance based on their individual circumstances
Request resources for support if needed

Special Populations and Considerations

Premature Infants

Premature infants metabolize ethanol at a slower rate than adults, and apart from careful observation, prevention of excessive heat loss, and awareness of signs of hypoglycemia, no particular precautions seem indicated when premature infants are born after treatment of the mother with ethanol during labor. However, extra caution is warranted for ongoing exposure through breast milk.

Mothers with Substance Use History

Women with a history of alcohol problems require special support. Research indicates they may have different physiological responses to alcohol that could affect their milk production and their infant’s wellbeing. These mothers benefit from:

Additional counseling and support
Alternative coping strategies
Close monitoring of infant growth and development
Connection with appropriate support services

Future Research Directions

Several areas require further investigation:

Long-term neurodevelopmental outcomes in children with varying levels of alcohol exposure through breast milk
Sex-specific differences in how infants respond to alcohol exposure
Genetic factors that may influence infant vulnerability
Optimal guidelines for different populations and circumstances
Biomarkers for identifying at-risk infants

Conclusion: Balancing Information with Support

The research on alcohol and breastfeeding presents a nuanced picture. While occasional drinking while breastfeeding has not been convincingly shown to adversely affect nursing infants, regular or heavy consumption poses clear risks. The key findings suggest that:

Occasional, moderate alcohol consumption (one drink) with appropriate timing is unlikely to harm a healthy, full-term infant
Waiting 2-3 hours per drink before nursing minimizes infant exposure
Heavy or frequent drinking can negatively affect milk supply and infant development
Individual factors in both mother and baby influence alcohol metabolism
The safest option remains abstaining from alcohol while breastfeeding

For mothers navigating these decisions, the most important factors are having accurate information, understanding their individual circumstances, and maintaining open communication with healthcare providers. The goal is to support both maternal autonomy and infant wellbeing, recognizing that each family’s situation is unique.

Rather than judgment or rigid rules, what mothers need is evidence-based information that empowers them to make informed choices. Whether a mother chooses complete abstinence or occasional moderate consumption with careful timing, she deserves support and accurate information to guide her decision.

The research continues to evolve, but current evidence supports a harm-reduction approach that prioritizes infant safety while acknowledging the realities of modern parenthood. As we await further research, particularly on long-term outcomes, healthcare providers and lactation consultants should continue to offer balanced, evidence-based guidance that helps mothers make the best decisions for their families.

References

National Center for Biotechnology Information. (2025). Alcohol – Drugs and Lactation Database (LactMed®).
Haastrup, M. B., Pottegård, A., & Damkier, P. (2014). Alcohol and breastfeeding. Basic & Clinical Pharmacology & Toxicology, 114(2), 168-173.
Centers for Disease Control and Prevention. (2025). Alcohol and Breastfeeding.
University of California – Riverside. (2023). Drinking alcohol while breastfeeding impacts health of newborns. ScienceDaily.
Mennella, J. A., & Beauchamp, G. K. (1991) – New England Journal of Medicine, 325(14), 981-985. The transfer of alcohol to human milk: Effects on flavor and the infant’s behavior.
Gibson, L., & Porter, M. (2020) – BMC Research Notes, 13(1), 1-4. Drinking or smoking while breastfeeding and later developmental health outcomes in children.
Atuyambe, L. M., et al. (2025) – a scoping review. Women’s Health, 21. Maternal smoking and alcohol use in association with breastfeeding initiation, duration, and infant health
Mennella, J. (2001) – Alcohol Research & Health, 25(3), 230-234. Alcohol’s Effect on Lactation.
Northwestern Medicine. (n.d.). Pumping and Dumping Myths.
Ford, L., et al. (2013). Elimination Kinetics of Ethanol in a 5-Week-Old Infant and a Literature Review of Infant Ethanol Pharmacokinetics.
Burd, L., Blair, J., & Dropps, K. (2012) – Journal of Perinatology, 32(9), 652-659.. Prenatal alcohol exposure, blood alcohol concentrations and alcohol elimination rates for the mother, fetus and newborn.