Why should I stop smoking if I’m pregnant?

Quitting smoking is the best thing you can do for your baby.

When you smoke, you breathe in over 4,000 chemicals from the cigarette. The smoke goes from your lungs, into your bloodstream and that blood flows to your placenta and umbilical cord.  This causes your placenta to not work as well as it should and will affect your baby’s growth and health.

The chemicals from the cigarette smoke also stop essential nutrients from reaching your baby. This affects:  

  • your baby’s heart, making it work harder
  • your baby’s growth rate
  • the development of your baby’s brain

Effects on your baby’s health

If you smoke during pregnancy, your baby:

  • is at increased risk of stillbirth
  • is more likely to be born early (prematurely; before week 37 of the pregnancy), which can cause feeding, breathing and health problems
  • won’t cope as well with any birth complications
  • is more likely to be born underweight and less healthy. On average, babies of smokers are 200g (8oz) lighter than other babies. A low birth weight adds to the risks of stillbirth, and makes your baby weaker and at greater risk of disease with a higher risk of hearing loss, learning difficulties and sight problems, as well as cerebral palsy
  • is more likely to have a problem keeping warm
  • is at increased risk of cot death
  • is more likely to get infections as a child, such as inflammation of the middle ear, and have health conditions that require hospital treatment, such as asthma

Low birth weight in babies is also linked to problems that develop as an adult, such as:

Effects on your health

If you smoke during pregnancy: 

  • you’re more likely to have morning sickness
  • you’re more likely to have complications during the pregnancy – for example, an ectopic pregnancy (when a fertilised egg implants itself outside the womb)
  • your risk of miscarriage and having a stillbirth is increased
  • your risk of a premature birth is increased
  • you’re at increased risk of placental abruption (when the placenta separates from your womb before your baby is born), which is dangerous for both you and your baby

Smoking also increases your risk of heart disease as smokers are twice as likely to have a heart attack than people who have never smoked. Smoking is responsible for one in every five deaths in adults aged over 35 in England.

Stopping smoking

The sooner you stop smoking, the better, but it's never too late. Even stopping in the last few weeks of your pregnancy can benefit you and your child. 

For free help, support and advice on stopping smoking, you can call the confidential NHS Smokefree Pregnancy helpline on 0800 169 9 169. The helpline is open Monday-Friday 9am-8pm and Saturday & Sunday 11am-5pm.

You can also speak to your:

  • midwife
  • health visitor
  • GP
  • obstetrician
  • practice nurse
  • pharmacist

They can provide information about your local NHS Stop Smoking Service. This service offers one-to-one or group sessions with trained stop smoking advisers. Many services also have a pregnancy stop smoking specialist who can help you to quit.

The Smokefree website has more information about smoking and pregnancy.

Read the answers to more questions about pregnancy.

Further information:


Video: get support quitting

You can call the NHS smoking helpline or visit the Go smokefree website to find out about different services and support to help you stop smoking.

Media last reviewed:

Next review due:

Page last reviewed: 15/07/2014

Next review due: 14/07/2016