Research now proves that if a pregnant women smokes, she is more likely to have a premature baby or a baby which has a very low birth weight.
Babies born to mothers who smoked in pregnancy can also have smaller organs or poor lung functions. This is due to the large number of toxins which tobacco smoke contains. In addition, they may get ill more often than other babies or suffer with asthma or bronchitis.
It is also thought that passive smoking may be harmful to a foetus, but not to the same extent as if the mother smokes during pregnancy.