Cigarette smoking leads to both oral and inhalational exposure of breastfed infants to cigarette constituents, including nicotine, although no adverse effects due to ingestion of nicotine or other cigarette components through breast milk have been reported. There is some evidence cigarette smoking reduces milk volume and duration of breastfeeding. Mothers should therefore be discouraged from smoking while breastfeeding or, at a minimum, reduce smoking quantity and not smoke in the same room as the infant.
Nicotine replacement therapy (NRT) in the mother is considered to present a lower and more acceptable risk to the infant than exposure from cigarettes through inhalation and breast milk. However, this will only apply if the mother is not smoking cigarettes in addition to using NRT.