Smoking During Pregnancy: What Are The Risks?

14/08/2014 17:02 | Updated 20 May 2015

Smoking during pregnancy: risks and advice

If you smoke when you're pregnant, your baby smokes too.

Quitting smoking isn't easy, but it is one of the best things you can do to give your baby a healthy start in life, and with the right help and advice it can be more straightforward than you'd expect.

No matter how far into your pregnancy you are, it is never too late to stop smoking.

Why is it so dangerous to smoke while pregnant?

Every cigarette you smoke contains more than 4,000 chemicals, including nicotine, carbon monoxide, cyanide, lead and at least 60 cancer-causing compounds - all of which will be passed onto your baby.

When you inhale, the smoke travels through your lungs and into your bloodstream. That chemical filled blood then flows to your placenta, where it is passed to your baby through the umbilical cord, causing your baby to struggle for oxygen.

The nicotine in the smoke narrows blood vessels throughout your body, including those in the umbilical cord, effectively choking off the baby's oxygen supply. At the same time, most of the oxygen that your red blood cells should be carrying is replaced by harmful carbon monoxide.

Exposing your baby to cigarette smoke in this way can cause stillbirth, premature delivery and low birth weight

How will smoking during pregnancy affect my baby's...


Babies of women who smoke are, on average, 200g (about 8oz) lighter than other babies. Low birth weight can cause problems during and after labour, and puts your baby at a greater risk of cot death (Sudden Infant Death Syndrome).


Smoking restricts your baby's oxygen supply, which means her heart has to beat even harder every time you have a cigarette.


Your baby will be more at risk of getting ear infections such as inflammation of the middle ear in childhood.


Your baby will be at increased risk of asthma and other chest infections during childhood.


A recent study found that women who smoke during pregnancy increase their risk of having babies with smaller brains and who are more anxious and moody than other kids.

And that's not all...

If you smoke throughout your pregnancy, your baby will go through nicotine withdrawal once she's born. If you've struggled to give up, think about how much tougher it will be for your newborn. She is likely to be stressed and irritable and it may be difficult to stop her crying

How else will I benefit from quitting?

As well as reducing your risk of stillbirth, miscarriage, pregnancy complications (such as ectopic pregnancy), premature birth and placental abruption (when the placenta detaches from your womb), you will also have less morning sickness.

I'm already four months pregnant, is there any point in me quitting now as my baby's already been exposed to smoke?

The sooner you quit the better, but even if you only stop in the last few weeks of your pregnancy your baby will still benefit.

Smoking in the last four to five months of pregnancy is particularly harmful for your baby, so it's never too late to quit.

I don't smoke, but my partner does - should I ask him to stop smoking around me or am I being overly cautious?

You're not being overly cautious. Secondhand smoke can affect you and your baby while you're pregnant.

If you partner or anyone who lives with you smokes, it is important to ask them to stop smoking, as secondhand smoke can also cause low birth weight and increase the risk of cot death.

The NHS offers free specialist support to help you stop smoking while pregnant. You can ask your midwife, GP or local pharmacist for more information, or call the NHS Pregnancy Smoking Helpline on 0800 123 1044 (open 9am-8pm Monday to Friday and 11am-5pm at weekends).

Suggest a correction