Smoking While Breastfeeding

Although it is well known that smoking is harmful for everyone and especially dangerous for babies, some mothers find it very difficult to give up smoking completely. Should mothers who smoke breastfeed? Does nicotine cross into breast milk and if so, would formula be a safer choice? Or will breastfeeding help to protect a baby against some of the health risks of breathing in cigarette smoke?

This article looks at the official recommendations for smoking while breastfeeding, discusses how smoking affects breast milk and your baby, and includes suggestions for reducing the risks to the breastfed baby if a mother or her partner can’t stop smoking straight away. For specific information about nicotine see Nicotine in Breast Milk and for nicotine replacement products or e-cigarettes see Nicotine Therapy, Vaping and Breastfeeding.

Can I smoke while breastfeeding?

Breastfeeding can help to protect your baby from some of the health risks and infections caused by passive smoking (being exposed to secondary smoke). As such, current health guidelines advocate continuing to breastfeed if you smoke with a number of recommendations to be aware of to protect baby from breathing in any side smoke.¹²³⁴

Recommendations to protect your baby from cigarette smoke and nicotine

• Stop smoking or try to cut down.⁵ A selection of organisations offering tips to help you stop smoking in the UK include; Smoking Cessation (NICE, 2018); Smoking, Smoking Cessation and Breastfeeding (Breastfeeding Network, 2019); Smokefree (NHS Department of Health [accessed Oct 2020].
• Don’t smoke in the home or car or let anyone smoke around your baby.⁶⁷ Smoking in another room of the house is unlikely to protect your baby significantly as smoke travels throughout a home and lingers in the furnishings.⁸
• Minimise smoke contact for your baby. Changing clothes and washing hands after smoking will help minimise a baby’s exposure to smoke (CDC, 2019). Lactation consultant Denise Fisher suggests covering hair with a scarf, keeping a smoking shirt to protect your own clothes while you smoke, and washing hands and face after smoking.⁹
• Don’t share a bed with a baby if you (or a partner in the bed) smoke as this increases the risk of sudden infant death syndrome.¹⁰
• Smoke straight after a breastfeed not before. The longer the time between smoking and the next breastfeed, the less nicotine will be in your breast milk (AAP, 2012).
• Nicotine replacement therapy helps some mothers to stop smoking. See Nicotine Therapy, Vaping and Breastfeeding for a review of nicotine patches, gum, inhaler, and sprays, and for information about e-cigarettes and vaping. And see Nicotine in Breast Milk for more information on the effects of nicotine.
• Check your baby’s weight gain regularly as some resources suggest smoking can reduce fat levels in breast milk and affect milk supply. How to Make More Breast Milk provides ideas to maximise a milk supply if there are any issues.

Health risks of smoking around babies

Babies exposed to cigarette smoke are at a greater risk of

• Sudden infant death syndrome (SIDS)¹¹¹²
• Having respiratory illnesses, tremors and muscle rigidity¹³
• Having ear and sinus infections, pneumonia, asthma, bronchitis, and lung cancer¹⁴
• Getting colic, being fussy, having more allergies, doing less well at school and having a stronger predisposition to become smokers themselves (Bonyata, 2018)
• Childhood obesity and thyroid dysfunction¹⁵¹⁶
• A shorter breastfeeding relationship due to a combination of several possible factors including mothers perceiving their milk as not good enough, increased colic and less sleep for their baby.¹⁷

Risks of breastfeeding and smoking for the mother

• Smoking increases the risk of breast abscess and inflammation and mastitis in the ducts behind the nipple (periductal mastitis)¹⁸¹⁹
• Smoking and nicotine are risk factors for nipple vasospasm. This is when the blood vessels in the nipple suddenly tighten causing pain after breastfeeds, see Nipple Vasospasm and Breastfeeding.
• Smoking after the birth of your baby may be associated with relapses of Crohn’s disease for a mother (Wambach and Riordan, 2020).
• Smoking may affect the let-down reflex (when milk is released from the breast), milk supply and baby’s weight gain (Wambach and Spencer, 2020 p337) however one researcher found the evidence for these effects was weak.²⁰

Benefits of breastfeeding for your baby

Breastfeeding is known to have significant health benefits for all babies because it allows normal development of the brain and body systems. It is thought particularly valuable that babies who are subjected to passive smoking receive these health benefits to help cancel out their increased risks of infection.²¹ Breastfeeding can help normalise a baby’s blood levels of important antioxidant vitamins such as A, C and E and two studies have indicated improved lung function in children of smokers who were breastfed up to ten years of age.²² Formula doesn’t have any of these benefits and carries its own health risks.

How does smoking increase SIDS?

#1 Smoking in pregnancy

One study of data from 2002 found that up to a third of SIDS deaths were connected to smoking during pregnancy.²³

#2 Smoking around baby

Tobacco contains about 600 different ingredients (e.g. arsenic, carbon monoxide, formaldehyde, tar, lead and nicotine) which create thousands of undesirable chemicals when they burn.²⁴ Once smoked, these chemicals travel around the home and cling to your skin and hair, clothing and soft furnishings so that your baby breathes them in long after the cigarette is finished. Passive smoking harms a baby’s breathing, lung function, brain and heart development putting them at a much higher risk of those respiratory infections that are connected with sudden infant death syndrome.²⁵

Nicotine is thought to play a key role in increasing the risk of SIDS by reducing the baby’s ability to maintain their breathing during low oxygen (hypoxic) episodes.²⁶

#3 Smoking and co-sleeping with baby

It’s important not to sleep in the same bed as your baby if you or your partner smoke as this increases his risk of SIDS.²⁷ On sharing a room if you smoke, the authors of Sweet Sleep say:

Even if you or your partner smokes, most research and health organisations still suggest keeping your baby in your room at night for at least the first half-year. But you can minimise your baby’s nighttime exposure to smoke by keeping his bed away from yours, by bringing him into your bed only for feeds, and by staying between him and a partner who smokes.

See Bed-Sharing With Baby for further information on safe sleep.

How does smoking affect breast milk?

Smoking or passive smoking by the mother can cause:

• Nicotine in breast milk (and other chemicals). When breathed in to the mother’s lungs, nicotine—a toxic, addictive chemical naturally found in tobacco plants—is rapidly absorbed into the mother’s blood, and the baby’s if he is passive smoking, along with tar, carbon monoxide and many other by products.²⁸ High levels of nicotine reach the brain in 10–20 seconds from one “puff”.²⁹ From the blood nicotine quickly diffuses into breast milk. For a review of the ways nicotine can affect a baby via breast milk, how long it stays there, and how to minimise the effects of nicotine see Nicotine in Breast Milk. For information about smoking marijuana see Smoking Weed While Breastfeeding.
• A lower fat content of breast milk which may affect infant growth and weight gain.³⁰³¹
• Smokey/nicotine tasting and smelling milk which may predispose children to like the taste of cigarettes.³²³³
• Lower iodine levels in breast milk  are described in a paper by Laurberg et al ³⁴ and this can increase the risk of iodine deficiency-induced brain damage. The authors advise against smoking for breastfeeding women, if they do, iodine supplements should be considered.
• Lower vitamin C in breast milk see Vitamin C and Breastfeeding.

Despite these changes Mennella et al say breast milk remains the ideal food even if a mother smokes:

Although lactating women who smoke are advised to stop smoking, breast milk remains the ideal food even if the mother does not stop smoking, because there is little evidence to suggest that breastfeeding from a mother who smokes has adverse effects on the infant (although there are risks related to smoking-induced reductions in milk iodine content). It should be emphasized that the lack of evidence may be attributable to the paucity of research.

Summary

Smoking is a serious health risk to your baby and a risk factor for SIDS. The ideal situation is to stop smoking. If you do smoke, breastfeeding can help protect your baby against some of the health problems associated with passive smoking. However, nicotine is readily breathed in and readily enters breast milk and may cause your baby to have difficulty sleeping, more colic, an increased heart rate, and a higher risk of SIDS. The impact of other toxic chemicals entering breast milk from smoking needs more research. It’s important to protect your baby from smoke as much as possible and you can help to lower their nicotine exposure via your milk by smoking straight after a breastfeed. Nicotine replacement therapy avoids the risk of passive smoking but e-cigarettes and vaping are still not well researched and their risks haven’t been studied.