Smoking and breastfeeding

Breastfeeding has important health benefits for both infant and mother. Mothers who smoke are less likely to start breastfeeding their babies than non-smoking mothers,109 and tend to breastfeed for a shorter time. The more cigarettes smoked, the sooner the baby is weaned. These associations remain after adjustment for social class.

In breastfeeding mothers who smoke, milk output is reduced by more than 250 ml/day111 compared with nonsmoking mothers. The composition of milk can also be affected: one study found that milk from mothers who smoked contained lower levels of lipids than milk from non-smokers.

Passive smoking also appears to influence breastfeeding. Non-smoking women exposed to other people’s tobacco smoke stop breastfeeding sooner than those who are not exposed.

The effect of smoking on breastfeeding may be mediated by nicotine regulation of the hormone prolactin. Prolactin is essential for the initiation and maintenance of milk production by the mother. Breastfeeding women who smoke have lower levels of prolactin than those who do not smoke.
Nicotine has been shown to inhibit the production of prolactin It seems plausible that in mothers who smoke, prolactin production might be reduced, resulting in poorer milk supply and an increased likelihood of giving up breastfeeding earlier.