Today is National No Smoking Day, so there's no better time, especially now you are pregnant to join millions of others and kick the habit. You probably already know that smoking increases your risk of lung cancer and heart attacks. But did you know that women who smoke are more likely to develop cancer of the cervix, and that smoking is to blame in some way for one in three middle-aged deaths?

If you smoke when pregnant you are harming your baby as well as yourself. A baby born to a smoker is:

• More likely than other babies to be abnormal in some way
• More likely to have an unhealthy placenta
• Twice as likely to be born prematurely
• Three times more likely to be underweight at birth (even if he is born on time)
• More likely than other babies to die suddenly in the first year of his life (a cot death)

Do not be misled into thinking that labour with a small baby is easier. A small baby has less strength to cope with labour, and runs a greater risk of dying at this time. Being born small can affect a baby’s health well into adulthood.

How smoking harms your baby

Each time you smoke a cigarette you breathe in a gas called carbon monoxide. This gas interferes with the transport of oxygen in your blood, and your baby’s supply of oxygen is reduced. Without a good supply of oxygen, your baby’s growth may be stunted.

The nicotine in cigarettes causes further harm. Nicotine narrows the blood vessels in the placenta, and this reduces still more the amount of oxygen and nutrients flowing to your baby. Nicotine also makes your baby’s heart beat faster. Recent research has shown that the nicotine from each cigarette you smoke passes to your baby and collects in the fluid in which he floats.

By smoking cigarettes low in carbon monoxide, nicotine and tar you may slightly reduce the effects of smoking on your baby.

For many women, cigarettes offer a short escape from the pressures of everyday life and giving up smoking is not easy. But for the sake of your baby you have to try, or at least to cut down. It is never too late in pregnancy to stop, or to reduce the number and strength of cigarettes. Your baby will immediately feel the benefits.

There is plenty of support and advice available to women who want to stop smoking. Ask your midwife for information about local help or telephone Quitline on 0800 002200, or try these websites: The official No Smoking Day website, HealthNet’s smokenders pages.