Why doctors say smoking in pregnancy is bad for you

Pregnant smokers who were offered £400 of shopping vouchers were more likely to give up, new research shows.

The Royal College of Midwives said offering rewards for taking up healthy behaviours was "not ideal" and expensive.

But the trial of 600 women showed that more than 20% of those offered vouchers did stop smoking, which researchers say could save the NHS money overall.

Why do doctors say it's important women give up smoking when they are pregnant?

Smoking is always unhealthy but the NHS says there are specific reasons why expectant women should quit.

For help and information on cigarettes and tobacco, visit BBC Advice

For many years tobacco advertisers sold the "health benefits" of cigarettes - and people, including pregnant women, were not educated as much as we are today about the dangers of smoking.

See some of the "outrageous" ways smoking was promoted.

Now medical experts know much more about the problems linked to smoking while pregnant.

'Healthy start'

"Protecting your baby from tobacco smoke is one of the best things you can do to give your child a healthy start in life," advice from the NHS explains.

They say that there are more than 4,000 chemicals in cigarettes and many of these can harm an unborn baby.

It can also interfere with the oxygen supply to the baby, requiring the heart to do more work.

Stopping smoking can ease morning sickness and increases your chances of a healthy pregnancy and baby.

There are other benefits to quitting cigarettes, including a reduction in the risk of stillbirth, a premature birth and cot death or sudden infant death.

Later life

Doctors also say that by quitting smoking, a parent can increase the chance of their baby having a healthier life.

"Continuing or returning to smoking after birth increases the risk of cot death and exposes your child to health risks including respiratory infections, ear infections, and asthma," says the charity Tommy's, which funds research into stillbirth, premature birth and miscarriage.

Second-hand or passive smoking can also reduce birth weight and make it more likely for a baby to need treatment of bronchitis and pneumonia.

"More than 17,000 children under the age of five are admitted to hospital every year because of the effects of second-hand smoke," say the NHS.

Why smoking not drinking?

When it comes to alcohol, opinion is still divided about exactly how much pregnant women can drink and still stay safe.

The Department of Health's guidance says that women should avoid alcohol altogether, but says that if they choose to drink, they should stick to one or two units of alcohol once or twice a week to minimise the risk to the baby.

The National Institute for Health and Care Excellence (NICE) says women should have no alcohol at all during the first three months of pregnancy because of the risks of miscarriage.

For the rest of pregnancy they say to drink no more than one or two units of alcohol once or twice a week.

How to quit

Always seek medical advice when looking to give up smoking as some medication, such as some stop smoking tablets are not recommended during pregnancy.

Manufacturers also recommend that pregnant women also avoid liquorice flavoured nicotine replacement therapies.

GPs, midwives, pharmacists and specialist stop smoking advisors should all be able to offer suitable support.

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