This is one of the most common questions sent in to our website. Many women ask if it is safe to smoke while they are breastfeeding. Smoking is relatively common during pregnancy, with about 10% of all women smoking at some point during their pregnancy. The rates are even higher among women with psychiatric illness. While many women may be able to stop smoking or reduce their intake during pregnancy, most women resume smoking during the postpartum period. And women who suffer from postpartum depression are at even higher risk for smoking relapse.
Nicotine and other chemicals from the tobacco are transferred into the breast milk at relatively high levels. The amount of nicotine to which the infant is exposed depends on the number of cigarettes consumed by the mother per day and also on the time interval between the last cigarette and the beginning of breastfeeding. Nicotine also accumulates in the breast milk (milk/plasma ratio 2.9), and some might be surprised to learn that the amount of nicotine transferred into the breast milk is more than double the quantity transferred through the placenta during pregnancy.
Women are strongly encouraged to breastfeed but women who smoke are more likely to have a lower milk supply, and those who do breastfeed tend to wean their babies earlier than women who don’t smoke. Studies indicate that smoking more than 10 cigarettes per day decreases milk production and alters milk composition. Furthermore, breastfed babies whose mothers smoke more than 5 cigarettes daily exhibit behaviors (e.g. colic and crying) that may promote early weaning.
In addition, because smoking is associated with sleep disturbances in adolescents and adults, researchers have begun to look at the sleeping patterns of babies breastfed by mothers who smoke. They found that the infants of mothers who smoke just before nursing have shorter sleep times and altered sleep architecture.
Most studies focus only on the effects of nicotine on the nursing infant; we have little information on how the breastfeeding infant may be affected by the other toxic chemicals in found in the breast milk of women who smoke, including arsenic, cyanide, formaldehyde, and lead.
In addition to exposure to nicotine and tobacco byproducts in the breast milk, there is well-defined literature regarding the risks children incur as a result of passive, or secondhand, exposure to smoke, including increased susceptibility to Sudden Infant Death Syndrome (SIDS), development and/or exacerbation of allergic diseases, such as asthma, and more recurrent and chronic respiratory illnesses. Less understood are the risks of thirdhand smoke, the residual nicotine and potentially toxic tobacco-derived chemicals left behind by tobacco smoke on surfaces including hair, skin, clothes, furniture, carpets, and walls.
What about E-Cigarettes?
Electronic or e-cigarettes are relatively new, so we do not have a lot of long-term data on its health effects. One thing that concerns me is that people often assume that e-cigarettes are safer than smoking regular cigarettes. While there might be certain health advantages to e-cigarettes, they deliver the same levels of nicotine to the smoker. Thus, we must conclude that e-cigarettes carry many of the same risks as regular cigarettes and are not a better option for nursing mothers.
Ruta Nonacs, MD PhD
Mennella JA, Yourshaw LM, Morgan LK. Breastfeeding and smoking: short-term effects on infant feeding and sleep. Pediatrics. 2007 Sep;120(3):497-502.
Primo CC, Ruela PB, Brotto LD, Garcia TR, Lima Ede F. Effects of maternal nicotine on breastfeeding infants. Rev Paul Pediatr. 2013 September; 31(3): 392–397.