Smoking

Apart from the well-known dangers that smoking is posing to anyone, such as increased risk for heart disease and cancer, women who smoke during pregnancy are at greater risk for giving birth to babies with low birth weight.

On average, babies born to women who smoked during pregnancy are statistically significantly smaller than those born to women who don't smoke. Low birth weight is one of the leading causes of infant illness and disability, and of stillbirth.

Evidence that cigarette smoking may have other harmful effects on the fetus is more controversial, but some problems associated with smoking include ectopic pregnancy (where the fertilised egg implants outside the womb), miscarriage, premature labour and birth, placental abruption, vaginal bleeding, and cot death. 

There are even some studies that are showing that smoking during pregnancy can harm a child's mental development and behaviour, leading to a short attention span and hyperactivity. Other research shows that certain birth defects may be more common in babies whose mother smoked during pregnancy. For example, a number of studies have shown a strong link between smoking in pregnancy and babies born with a cleft lip and/or palate.

The further into pregnancy you smoke, the greater your risk of complications. For example, if a pregnant woman stops smoking during the first half of her pregnancy, her baby will most likely be born a normal weight. If she continues to smoke throughout the pregnancy, she'll probably have a low birth weight baby. So if you're a smoker and have not succeeded in quitting so far, stopping now, or at the very least cutting down on the number of cigarettes you smoke a day, can still benefit you and your baby.