The risks of secondhand smoke

Secondhand (passive) smoke is highly toxic. More than 80% of secondhand smoke is invisible and doesn’t smell.

What are the risks of secondhand smoke?

Secondhand (passive) smoke can affect you and your baby before and after their birth.

Secondhand smoke can increase the risk of:

Babies whose parents smoke are also more likely to be admitted to hospital for infections that can affect their breathing, such bronchitis and pneumonia, during the first year of life.

If you are a smoker, you will also find it harder to quit if someone living with you is also a smoker.

It doesn’t matter how careful others think they are about keeping smoke away from you. If someone smokes in your home, you and your baby still get the harmful poisons. Opening windows and doors or smoking in another room will not make it safe.

How do I know if I’m affected by secondhand smoke?

Your midwife will measure the levels of carbon monoxide (CO) in your body with a CO monitor at your antenatal appointments. This will show if you are being exposed to secondhand smoke, as well as if you smoke yourself.

What can I do about secondhand smoke?

The smoker in your home may not be aware of how their smoking affects you and your baby. It may help to talk to them about quitting smoking for you and your baby’s sake, if not theirs. There is support available, if they need it.

You could also try to:

  • avoid going to places where you know people will be smoking indoors
  • ask drivers not to smoke in the car or take different transport
  • tell visiting smokers to smoke outside with the door closed behind them, make sure nearby windows are also closed
  • keep an umbrella, raincoat and or wellies by the door so there are no excuses for people not to smoke outside even if it's raining
  • have information and stickers from NHS Smokefree around your home
  • call these free helplines for advice on how to keep you and your baby safe from other people's smoke: Quitline on 0800 00 22 00 or Smokefree helpline on 0300 123 1044.

More on the effects of smoking


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

NHS Smokefree

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

Hide details

    Last reviewed on February 14th, 2020. Next review date February 14th, 2023.

    Was this information useful?

    Yes No


    Please note that these comments are monitored but not answered by Tommy’s. Please call your GP or maternity unit if you have concerns about your health or your baby’s health.
    • By Claire (not verified) on 12 Nov 2019 - 22:24


      My name is Claire. I work in a male dominant trade, and am one of the only females on the shop floor. My job does not have a policy against smoking in the shop. Most of the employees smoke. I’ve asked them not to smoke around me, but they still smoke in the area. Can I wear a mask or something to protect my baby?

    • By Ash (not verified) on 13 Jun 2019 - 23:52

      I am 12 weeks pregnant, my flat mate has previously and today smoked in my room out the window and all the other one more person smokes in the kitchen, I’m worried this is going to cause problems to my baby, I told her today about the smoke but just concerned problems may occur, Cose I’ve been surrounded by it before i knew of my pregnancy, I did a carbon monoxide exposure test and it was low, but just wanted to get some advice on this please.

    • By Helen (not verified) on 9 Feb 2019 - 20:16

      When i was 2 months pregnant, i and hubby went to see some of his friends when we travelled down to his hometown in a joint where almost everyone smokes. We stayed there for close to 4 hours and at a time i had to excuse myself to get clean air. Now I'm 4 months pregnant. I just want to know if that will affect my baby. Thank you

    • By Amy Douglas (not verified) on 23 Dec 2018 - 19:56

      I work in an office where a colleague goes out several times a day for cigarettes. Her desk is joined to mine so when she comes back all I can smell is cigarette smoke. Which is making me feel really sick, and I’m also concerned about her still breathing out toxic fumes. Is this classed as second hand smoke and do I have any rights at work ?

    • By Midwife @Tommys on 4 Jan 2019 - 16:36

      Hi Amy,
      It would not necessarily be second hand smoke as she is not actively smoking next to you. However your employer has a duty to make sure the environment you are in is safe and comfortable for you, as this is making you feel sick I would suggest if you can speak with your manager or HR about the possibility of moving desks or managing this.
      Bets wishes
      Tommy's midwife

    • By Ellie (not verified) on 20 Oct 2018 - 17:16


      I need some advice. I have a 6month old and we are off to see husband in laws family. The family are heavy smokers and even though we are not staying with them I am really worried about them smoking around bambino and him experiencing second hand smoke. Am I being precious? Is there any advice you could give?

    • By Midwife @Tommys on 23 Oct 2018 - 12:32

      No I don't think you are being precious. We have so much evidence that smoking is harmful to children even when it is second hand smoke. I think you should politely request that your in laws respect the right of the children to clean air and that they don't smoke around the children.

    • By Sweety (not verified) on 6 Jul 2018 - 08:10

      My small apartment is adjacent to another flat where a boy smokes in his verandah. I smell the smoke in my room which is well ventilated but the window I have is adjacent to the boy's verandah. It is once or twice per day. Am I at risk? 14 weeks pregnant now!

    • By Midwife @Tommys on 9 Jul 2018 - 11:49

      I don't think that there is anything that you can do here. You could try talking to your neighbour asking him to be mindful that you are concerned. But it is good that your flat is well ventilated and that you are keeping away from smoky venues as much as you can.

    • By Cal (not verified) on 27 Jun 2017 - 12:22

      My mum smokes and I'm worried about going to visit her due to this. It's her house and I can't ask her to go outside and smoke. She keeps it to the kitchen and doesn't smoke anywhere else but if I can't ask her to go out side I feel awkward visiting. When I go I'm usually there a couple days as it's so far away. This is my second pregnancy and my rainbow. I don't want to do anything to harm myself or the baby.

    • By Midwife @Tommys on 27 Jun 2017 - 12:38

      Hi Cal
      If you feel unable to discuss this with your mum directly (I am sure that she would understand your worry) then it would be a good idea to ensure that the house is well ventilated - with windows open to help fresh air to circulate, especially in the kitchen where your mum smokes. It would also be a good idea to close the door of the room that she is smoking in too, to encourage the smoke to travel out of the window and not into other rooms of the house.
      Please get your midwife to do a carbon monoxide test on your at your next antenatal appointment so that the levels that you are exposed to can be measured. It might encourage your mum to smoke less around you if the results are higher than average.
      Please take good care of yourself!

    • By Cal (not verified) on 27 Jun 2017 - 14:12

      Thank you for the advice, The door thing is tricky too but I will try and do what I can to open/close doors windows. She doesn't open many.

    Add new comment