When a pregnant woman smokes, so does her baby. Carbon monoxide and nicotine (among other poisonous substances) are carried through the bloodstream from mother to the baby, leading to lower levels of oxygen intake, a higher pulse rate, and other ill effects. Nicotine exposure in utero may inflict lasting brain damage.
Smoking during pregnancy leads to an increased risk of miscarriage; babies being born underweight, premature or stillborn; or dying in their first year of life.
Children whose mothers smoked during pregnancy also have a higher risk of sudden infant death syndrome (SIDS), middle-ear disease, respiratory illnesses and asthma. Children of women who smoke during pregnancy are also more likely to become smokers later in life.