Q: Does smoke pass through the breast milk to the baby when breastfeeing?

A: Smoke does not pass through the breast milk to baby, but the nicotine and other chemicals in the cigarette smoke do pass to the baby through breastmilk.

Smoke does not pass through the breast milk to baby, but the nicotine and other chemicals in the cigarette smoke do pass to the baby through breastmilk. Moreover, the smoke will stick to clothing and skin and affect baby in that way. Even if mom does not smoke around baby there can be an increased risk of illness and lung disorders due to the latent smoke on mom.
Second hand smoke is also an issue for a newborn baby. Even if mom does not smoke, the second hand smoke can be inhaled and the nicotine passed through the breast milk to baby. Nicotine is a drug that causes addiction. This is not reserved for the smoker. The baby can also become addicted to the nicotine.
It is important to note that mothers who smoke should still breastfeed. The positive effects of the breast milk far outweigh the negatives in the beginning months of life. The first breast milk, or colostrum, passes antibodies from mother to baby. This is very important for the newborn, but is even more important for the newborn with a mother who smokes.
Babies who breastfeed with a mother that smokes often wean from the breast earlier than other babies. The mother will produce less milk when she smokes than if she chooses not to smoke during breastfeeding. The milk production is lowered due to the lowered production of prolactin. Prolactin is the hormone that is responsible for milk production. There are also reports that link cigarette smoking while breastfeeding with lower than normal iodine levels. If the baby does not receive enough iodine, thyroid function could be impaired.