Smoking and pregnancy

This article is for women who smoke and are pregnant or trying to conceive. It explains the risks of smoking in pregnancy and how to give up.

Many women find that trying to conceive a baby or becoming pregnant are excellent motivations for giving up smoking.

Smoking is harmful to you even if you are not currently planning to have children. It's a risk factor for cancer and heart disease. It's also linked to other problems such as early menopause and premature wrinkles.

In addition, there are many other health risks to smoking during pregnancy, for both you and your baby.

Problems for you

Smoking reduces your chances of getting pregnant
Smoking reduces fertility in both men and women. Just five cigarettes a day can have an impact. Women smokers are twice as likely to be infertile (not conceive within 12 months of trying) compared to non-smokers. Men who smoke have reduced sperm count and quality. It's likely to take longer to conceive if you and your partner smoke. Smoking also reduces the success of fertility treatment such as in vitro fertilisation (IVF) working, if you do need it.

This may be because chemicals in cigarette smoke are poisonous to the testes and ovaries, and smoking may affect the production of sex hormones. It may even affect the meeting of egg and sperm, and cause problems with a fertilised egg implanting in the womb.

Smoking increases the risk of problems in pregnancy

You are more likely to have complications in pregnancy and labour if you smoke. These can include:

miscarriage - loss of the baby before 24 weeks
ectopic pregnancy - when the fertilised egg implants and grows outside the womb, usually in a fallopian tube; just one to five
   cigarettes a day increases the risk by 60 percent
premature detachment of the placenta - when the placenta comes away from the wall of the womb, which can cause the
   baby to die before or soon after birth
placenta praevia - when the placenta blocks the opening of the womb, which can cause bleeding or premature birth
pre-eclampsia - high blood pressure in pregnancy, which can affect the baby; in severe pre-eclampsia, the mother can die
premature labour - when labour begins before 37 weeks of pregnancy

Problems for the newborn baby
When you smoke during pregnancy, carbon monoxide in the cigarette smoke prevents oxygen from getting to the developing baby, so the baby is short of oxygen. This slows growth and affects brain development.

Smoking during pregnancy also puts the baby at risk of many other problems.

One-third of all perinatal deaths (deaths after 24 weeks of pregnancy and before the baby is four weeks old) are caused by smoking. The more cigarettes you smoke, the higher the risk for your baby. Problems can include:

being born too early - babies whose mothers smoke are twice as likely to be premature ie born before 37 weeks of pregnancy
low birth weight - this means being born weighing less than 2,500g, or 5lb 5oz; babies born to women who smoke are, on
   average, 200-250g lighter than those of non-smokers
physical birth defects - malformations of the mouth (cleft lip or palate), limbs, urinary system or genitals are more common
   in the babies of smokers

Problems during infancy and childhood
Damage to the baby during pregnancy may cause problems after birth.

If you smoke during pregnancy it increases the risk of sudden infant death syndrome (SIDS), or cot death. This is when a baby under 12 months dies and no cause can be found despite a detailed investigation. It's most common after one month and before six months. The risk of SIDS is three times higher if you smoke during and after pregnancy. Scientists don't know exactly why SIDS happens, but it may be caused by problems with the processes that regulate heartbeat and breathing. Smoking may affect the development of the baby's brain so that he or she is born before the brain can correctly regulate the heart and lungs.

Compared to babies of non-smokers, babies whose mothers smoked in pregnancy may also have less effective lungs, because their lungs did not develop correctly. Your baby may be more likely to have colic, which causes regular episodes of inconsolable crying in the baby.

If you continue to smoke after the birth, your child is at increased risk of:

asthma
chest infections such as croup and pneumonia
ear infections
childhood cancer
being small and light for his or her age
lower achievement at school

Breastfeeding

Breastfeeding meets all your baby's nutritional needs for the first six months of his or her life and has advantages for your baby's health, such as protecting against infection.

If you smoke, it can affect breastfeeding, reducing the amount of milk you produce by 250ml/day. This may be because nicotine affects the hormone prolactin, which you need to produce milk. The milk is also of poorer quality, containing lower levels of the fats your baby needs.

Mothers who smoke are more likely to give up breastfeeding earlier. This may be because changes in milk production and quality lead to problems with breastfeeding, possibly with an unsatisfied baby, so the mother switches to bottle feeding.

Help to quit

The Sure Start programme supports mothers who want to quit by providing advice from health professionals and support from the local community. Ask your GP or midwife for advice. Alternatively, he or she might refer you to a trained counsellor or a smoking cessation programme.

An independent charity called QUIT can help you kick the habit. There is a free confidential quitline and the website offers practical advice and tips, including advice for pregnant women.

It may be harder to stop smoking during pregnancy if your partner smokes, so you and your partner may choose to quit together.

Some people find acupuncture helpful, although there is little scientific evidence that this helps.

Nicotine replacement therapy (NRT)

NRT helps you to deal with nicotine withdrawal cravings by allowing you to absorb nicotine without taking in the toxic chemicals in smoke.

Ideally, you should try to quit without NRT, in order to reduce the amount of nicotine the developing baby is exposed to. However, doctors generally think that NRT is better than carrying on smoking while you are pregnant or breastfeeding.

Talk to your GP. He or she may recommend gum or a spray rather than patches because patches mean that the baby is continually exposed to nictotine. If you do need patches, you should take them off at night.

Key points

Smoking reduces both men's and women's fertility.
Smoking harms your unborn baby.
Smoking puts you health at extra risk in pregnancy.
Giving up as early as possible in pregnancy will benefit you and your baby - giving up at any time is better than continuing to smoke.