Tommy's PregnancyHub

What happens when a pregnant woman smokes?

Smoking in pregnancy is harmful to your baby. Quitting is one of the best things you can do to protect your baby’s health during pregnancy and after they are born.

Most people know that smoking is bad for you, but if you're a smoker and pregnant it can harm your growing baby too. In the UK, smoking in pregnancy causes up to 5,000 miscarriages and around 2,200 premature births each year. The good news is that there is lots of help available to quit.

Did you know?

Many women give up successfully. Smoking rates recorded at delivery have fallen to their lowest recorded level in England in 2019.

How does smoking during pregnancy affect babies?

When you smoke, your baby does too. Every cigarette contains 4,000 chemicals, which go into your lungs when you smoke. Once in your lungs, the nicotine, poisons and carbon monoxide cross the placenta to your baby.

How can smoking during pregnancy harm my baby?

Research shows that smoking in pregnancy may harm your baby in a number of different ways. These include:

Your child’s development

Smoking when pregnant can also affect your child as they grow up. Babies and children whose mothers smoke during pregnancy are also at great risk of:

  • sudden infant death syndrome (SIDS)
  • colic
  • infections in the airways
  • ear infections
  • asthma
  • conditions such as ADHD (attention deficit hyperactivity disorder).

Smoking during pregnancy has also been linked to psychological problems in childhood, disruptive behavior and poor educational performance.

Stopping smoking reduces all these risks.

Talking to your midwife about smoking

At your first antenatal appointment, your midwife will ask lots of questions about your lifestyle, including whether you smoke or have recently quit. You'll also be asked whether anyone in your household smokes.

It’s very important that you tell them if you smoke. Your midwife will not judge you if you are a smoker. They know how hard it is to stop and they will be very keen to help you in any way they can.

Find how you can get help to stop smoking in pregnancy

Smoking in Pregnancy: Communication with Women Working Group. 2015. Shared key messages.

Royal College of Physicians, Tobacco Advisory Group(2010) Ch 3. Effects of smoking on fetal and reproductive health. In: Passive smoking and children: A report by the Tobacco Advisory Group of the Royal College of Physicians. 

NHS Choices. Stop smoking in pregnancy. (Page last reviewed: 07/11/2019. Next review due: 07/11/2022)

The Royal College of obstetricians and gynaecologists (2015) Smoking in pregnancy

NICE (2018). Smoking: stopping in pregnancy and after childbirth. National Institute for health and care excellence

NHS Digital. Statistics on Smoking, England - 2019.

Review dates
Reviewed: 14 February 2020
Next review: 14 February 2023

This content is currently being reviewed by our team. Updated information will be coming soon.