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, right into your baby’s body. This causes your baby to struggle for oxygen and their tiny heart to beat even faster. 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. 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
  • is more likely to smoke when they’re older

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 detaches from your womb before your baby is born), which is dangerous for both you and your baby

Smoking also increases your risk of:

  • cancer: 9 out of 10 cases of lung cancer are caused by smoking
  • heart disease: smokers are twice as likely to have a heart attack than people who have never smoked

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. 

The carbon monoxide in cigarette smoke restricts your baby’s oxygen supply, so every time you smoke it makes your baby’s tiny heart beat harder. Once you stop smoking, you and your baby will feel the difference immediately.

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
  • 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 Go Smokefree website has more information about smoking and pregnancy.

Read the answers to more questions about pregnancy.

Further information:

 

Get support quitting

NHS Smokefree offers different services and support to help you stop smoking.

Media last reviewed: 18/09/2011

Next review due: 18/09/2013

Page last reviewed: 07/08/2012

Next review due: 07/08/2014