Smoking and breastfeeding: What happens to breast milk

As a new mother, you only want the very best for your baby. At the same time, breastfeeding often brings a lot of questions and uncertainty, especially if you smoke. Is smoking while breastfeeding even possible, or can it harm your baby? Does nicotine pass into the newborn’s body through breastfeeding? What specific effects can smoking while breastfeeding have on your child, and what is the best way to protect them? In this article, you’ll find answers to these and other important questions about smoking and breastfeeding.

Does nicotine pass into breast milk?

Smoking while breastfeeding affects not only the mother’s health, but also that of the breastfed child. Chemical substances such as nicotine, heavy metals, and nitrosamines pass from the mother’s blood into breast milk and therefore into the infant’s body. Unlike passive smoking, when smoking while breastfeeding the baby absorbs the harmful substance not only through the air, but also through food. In infants, the intake of nicotine and other harmful substances can lead to restlessness, colic, vomiting, and slowed weight gain, among other things².

How much nicotine reaches the baby

Does the same amount of nicotine pass into breast milk as is present in the mother’s blood? In fact, even more: nicotine can accumulate in breast milk, because it is less acidic than the mother’s blood³. In one study, the milk-to-plasma ratio was 2.9, meaning the nicotine concentration in breast milk was on average almost three times higher than in maternal plasma⁵. This is consistent with the observation that, in smoking mothers, a close correlation was found between nicotine concentrations in maternal blood plasma and breast milk⁴. The actual nicotine concentration in breast milk depends on how high the mother’s nicotine exposure is.

Why it takes longer for infants to break it down

Why does a single cigarette have a much longer-lasting effect on an infant than on the mother herself? The reason is not the Quantity, but the child’s metabolism. Newborns break down nicotine significantly more slowly than adults. The half-life of nicotine (that is, the time it takes for the amount of nicotine to be reduced by half) is around three to four times longer in newborns than in adults.

One possible reason for this is that the enzyme system is not yet fully developed. In adults, the enzyme CYP2A6 in particular plays an important role in breaking down nicotine. The lower or altered activity of this enzyme could contribute to nicotine remaining in the body longer in newborns⁶. In addition, nicotine is distributed differently in infants’ tissues than in adults’ tissues⁶. So if you smoke several times a day, your baby repeatedly takes in nicotine through breast milk. Their body cannot break it down as quickly, which means the nicotine stays in the body longer. As a result, your baby may hardly have any truly nicotine-free phase at all.

>> You may also like to read: How long nicotine stays in the body

Nicotine passes from cigarette smoke into breast milk via the mother’s bloodstream and is broken down in the baby’s body 3–4x more slowly.

What else changes in breast milk

Does smoking only change breast milk because of the nicotine it contains, or does it affect it in other ways as well? In fact, the composition of the milk itself also changes. Among other things, breast milk from mothers who smoke contains less fat and protein, both of which are important nutrients for the baby. Smoking also reduces the levels of vital antioxidants such as vitamin C and vitamin E, as well as the trace element iodine.

These nutrients play an important role in the infant’s growth, cell protection, and immune system. So the milk is not “only” contaminated with nicotine — at the same time, it also loses nutritional value and therefore important properties⁷. In addition, smoking can change the taste of breast milk, which may affect the baby’s feeding behavior. The protective effect of breastfeeding against respiratory illnesses can also be weakened by maternal smoking.

How nicotine affects a breastfed baby

Nicotine reaches the infant through breast milk and can affect sleep, digestion, and feeding behavior, among other things. The following symptoms may be observed in breastfed babies of mothers who smoke:

• Restlessness and sleep problems: Nicotine has a stimulating effect and can make babies more irritable and restless, making it harder for them to fall asleep. Their natural sleep rhythm may also be affected. Some infants sleep for shorter periods or less peacefully, seem nervous, or cry more often.
• Colic: Nicotine can affect the nervous system and the intestines, which may trigger abdominal cramps, bloating, nausea, or vomiting. It can also change the taste of breast milk, causing some babies to drink less or more reluctantly. If an infant is especially restless while breastfeeding, they may also swallow more air. This so-called aerophagia can further increase bloating and colic-like symptoms.
• Feeding difficulties: Some babies of mothers who smoke feed more reluctantly, for shorter periods, or at longer intervals. Alongside a possible change in the taste of breast milk, nicotine’s effect on the nervous system may also play a role. With higher nicotine exposure, an infant may appear unusually sleepy, weak, or unresponsive (so-called lethargy), making sucking less effective. At the same time, smoking can delay the let-down reflex and affect milk supply. As a result, the baby has to work harder while feeding and tires more quickly. Restlessness caused by nicotine can also make breastfeeding more difficult.
• Slower weight gain: If a baby takes in less food due to feeding difficulties or a lower available milk supply, this can affect weight gain. Nausea and vomiting can make feeding even more difficult. A changed taste of breast milk can also cause babies to drink less and therefore take in fewer nutrients.

These symptoms can have many different causes and are therefore not always linked to nicotine exposure. Teething, a temporary fussy phase, or an intolerance can also cause similar symptoms. If you smoke and often notice restlessness, sleep or feeding problems, digestive issues, or noticeably slow weight gain in your baby, it’s best to contact your midwife or pediatrician. That way, a medical professional can assess what might be causing it and what will help your baby best.

Nicotine can cause restlessness and sleep problems in a breastfed baby.

Smoking reduces milk production

Does smoking also affect the Quantity of the breast milk produced, or does it remain unaffected? Smoking can affect the mother’s milk production. In one study, the daily amount of milk produced by smoking mothers averaged 693 grams, while non-smoking mothers produced 961 grams⁸. That is a difference of 268 grams, or just under 28 percent. Other studies also show that smokers produce 200 to 300 milliliters less milk during breastfeeding than non-smokers⁹.

One possible reason is nicotine’s effect on prolactin levels. Prolactin is a hormone that regulates milk production. Smoking can affect hormonal regulation and thereby reduce milk supply⁹. A lower milk supply can make breastfeeding even more difficult. If your baby does not get full and several breastfeeding attempts are needed, this can be exhausting and stressful. Especially if you are already trying to reduce your cigarette consumption, this additional strain can increase cravings to smoke. The study mentioned also showed that the babies of smoking mothers gained less weight than the babies of non-smoking mothers⁸.

How strongly smoking actually affects milk supply can vary from mother to mother. Overall, however, there is a clear connection between smoking and lower milk production.

Breastfeeding despite smoking — yes or no?

There is no doubt that cigarette smoke is harmful to health. Your baby should ideally not come into contact with tobacco smoke and should be exposed to as few of the harmful substances it contains as possible. But what does this mean for you if you smoke? Should you stop breastfeeding or continue anyway? Even if you smoke, breastfeeding is generally still recommended. Ideally, the best thing for you and your baby is of course to quit smoking. But even if you’re not able to do that right now, that doesn’t automatically mean you have to stop breastfeeding. Breast milk contains many valuable nutrients and offers health benefits for your baby, including a lower risk of respiratory illnesses and sudden infant death syndrome (SIDS)¹.

So far, there is no scientifically established threshold for how many Quantity cigarettes smoked would cause the harmful substances in breast milk to outweigh the benefits of breastfeeding¹. If you smoke, you should therefore not give up breastfeeding for that reason alone. Even the breast milk of a smoking mother generally remains valuable for the baby because of its composition and the nutrients it contains².

What is especially important, however, is reducing your baby’s exposure to tobacco smoke as much as possible. If you’re currently unable to breastfeed and quit smoking completely at the same time, you can reduce the number of cigarettes and protect your baby from tobacco smoke as consistently as possible. Professional support can help you quit smoking or cut down.

How long should you wait to breastfeed after smoking?

There is no exact guideline for how long you should wait between smoking and breastfeeding again. What is clear, however, is this: the longer the time gap between smoking and breastfeeding, the better. That’s why it is recommended to breastfeed before smoking whenever possible and then smoke afterward, so you can make the most of the time until the next feeding³.

Nicotine passes into breast milk through the bloodstream. The half-life of nicotine in breast milk is around 90 minutes. This means that the amount of nicotine is reduced by about half after that time¹⁰. The Nicotine content in breast milk is highest about 30 to 60 minutes after smoking and then gradually decreases again. After around three hours, it has dropped significantly. Biopsychologist Dr. Julie Mennella therefore recommends waiting a few hours after smoking whenever possible before breastfeeding again¹¹.

After smoking, not only the nicotine level but also the concentration of carbon monoxide in the mother’s body and breath rises and is especially elevated during the first hour. Your baby should therefore, if possible, not come into contact with the mother’s exhaled air immediately after smoking¹⁰.

The Breastfeeding Lexicon recommends not smoking for at least two hours before breastfeeding¹. However, this is not considered a universally valid waiting time. As a general rule: if you smoke, it’s best to breastfeed directly beforehand and then leave as much time as possible before the next feeding.

Secondhand smoke after birth: the underestimated risk

Is the risk for your baby over as soon as they are no longer exposed to nicotine through breast milk? No, harmful substances from cigarette smoke can also enter your child’s body through the air, and for many babies this exposure even begins before birth: Through smoking during pregnancy, nicotine and other harmful substances pass through the placenta into the bloodstream of the unborn child. Infants growing up in a household with tobacco smoke inhale these harmful substances directly. Children breathe faster than adults and have a lower body weight. As a result, they absorb more harmful substances in proportion to their body size. At the same time, their detoxification organs are not yet fully developed, so certain harmful substances from tobacco smoke cannot be broken down as effectively⁷.

Your baby can also absorb the harmful substances from cigarette smoke through the air.

Children who are regularly exposed to tobacco smoke, for example, are more likely to develop middle ear infections and respiratory infections, and the risk of coughing, asthma, and allergies may also increase⁷. In addition, passive smoking is considered an important risk factor for sudden infant death syndrome (SIDS)³. You should therefore protect your child from tobacco smoke as consistently as possible and keep them away from people who smoke and smoke-filled rooms.

learn more about passive smoking

Quitting smoking while breastfeeding — what helps

The best way to protect your child while breastfeeding is to quit smoking completely. However, quitting is not always easy, because nicotine is highly addictive, and the first period with a baby can be especially challenging due to lack of sleep, stress, and new routines. But there are various support options that can help you:

• Doctor, pediatrician, or midwife: Your midwife can support you in quitting smoking in everyday life and work with you to develop strategies that fit your personal situation. If you do not manage to quit right away, she can also show you how to keep your child’s exposure to harmful substances as low as possible. If you experience severe physical withdrawal symptoms caused by nicotine or have questions about nicotine replacement therapy, medical advice is recommended. This includes nicotine patches, gum, and sprays. Whether and in what form these products are suitable while breastfeeding should always be clarified with a doctor.
• BIÖG telephone counseling: In Germany, you can reach the smoking cessation helpline of the Federal Institute for Public Health (BIÖG) at the free phone number 0800 8 31 31 31. There, you can receive individual advice as well as free information material and brochures.
• rauchfrei-info.de and iris-plattform.de: You can also find support for quitting smoking online. There are options for information, self-assessments, free online programs, and opportunities for individual guidance and exchange.
• Recognize triggers and change routines: Especially in the first few months after birth, lack of sleep, stress, and changes to your daily routine can make it harder to stay smoke-free. It can help to identify typical smoking triggers and consciously plan alternatives for those situations, such as a short walk, a glass of water, or another activity to keep your hands and mouth busy.

Nicotine replacement therapy (NRT) while breastfeeding: Nicotine replacement products also contain nicotine, which can pass into breast milk. The available data on the safety of NRT while breastfeeding is inconsistent⁴. While some sources consider it compatible with breastfeeding, others advise against it because of possible risks, including for the child’s lung development⁴. If you are considering nicotine replacement therapy, you should therefore discuss with your doctor whether it is suitable for you and, if so, which product may be an option. It should not be used without prior medical advice.

Medications for smoking cessation while breastfeeding: Medications such as bupropion and varenicline are used to help people quit smoking. Whether they are suitable during breastfeeding is viewed differently. Under certain conditions, bupropion may be used on its own and with close monitoring of the child^{12, 13}. For varenicline, however, there is currently insufficient data on its use while breastfeeding¹⁴. You should always discuss with your doctor whether medication support is an option for you.

learn more about quitting smoking with medication

E-cigarettes and Nicotine Pouches while breastfeeding: E-cigarettes are also not harmless to health during breastfeeding. Nicotine can also pass into breast milk this way. That is why it is recommended to stop using e-cigarettes while breastfeeding whenever possible³. If that is not possible for you, you should reduce consumption as much as possible and never vape near your child or indoors³. Nicotine Pouches are also not a safe alternative while breastfeeding, as the nicotine they contain can enter the bloodstream and therefore also breast milk³. Nicotine-free Pouches, on the other hand, contain no nicotine and can therefore be a possible alternative if the ritual of use helps you avoid nicotine.

Tips & strategies for quitting smoking

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More reasons to quit smoking

In addition to the risks associated with smoking and breastfeeding, there are other reasons,  why smoking is harmful and why it’s worth quitting:

• Smoker’s leg, smoker’s cough, and smoker’s lung are typical secondary illnesses, the risk of which decreases with every smoke-free year.
• The risks of passive smoking affect the people around you – partners, children, and colleagues breathe in the same harmful substances.
• Smoking during pregnancy harms two bodies and carries significant risks and consequences for the baby.
• Numerous benefits of quitting smoking for your body, mind, and wallet.