Smoking while pregnant exposes a woman and her unborn child to an increased risk of health problems. Australian studies indicate that about 11 per cent of women smoked during pregnancy in 2014. Passive smoking can also affect a pregnant woman and her child.
A woman who smokes while pregnant is at increased risk of a wide range of problems including ectopic pregnancy, miscarriage and premature labour. Women who smoke are twice as likely to give birth to a low birth weight baby compared to non-smokers. Low birth weight babies are at greater risk of death and are more vulnerable to infection, breathing difficulties and long-term health problems in adulthood.
The more cigarettes smoked during pregnancy, the greater the risk of complications and low birth weight. However, there is no solid evidence that cutting down on the number or strength of cigarettes smoked significantly reduces the risks to the fetus. Stopping smoking completely as early as possible is a much better option for the health of babies and their mothers.
Pregnancy complications from smoking
Some of the pregnancy complications more commonly experienced by women who smoke include:
- ectopic pregnancy – this is pregnancy outside the uterus, usually in the fallopian tube
- fetal death – death of the baby in the uterus (stillbirth)
- spontaneous abortion – known as miscarriage
- problems with the placenta, including early detachment from the uterine wall and blocking the cervical opening (placenta previa)
- premature rupture of the membranes
- premature labour.
Smoking during pregnancy – effects on the fetus
Every time a pregnant woman smokes a cigarette, it cuts down oxygen to her unborn baby and exposes the baby to a cocktail of chemicals, including chemicals that cause cancer.
Some of the many damaging effects of cigarette smoke on the fetus include:
- reduced oxygen supply due to carbon monoxide and nicotine
- retarded growth and development
- increased risk of cleft lip and cleft palate
- decreased fetal movements in the womb for at least an hour after smoking one cigarette
- impaired development and working of the placenta
- changes in the baby’s brain and lungs.
Problems at birth due to smoking during pregnancy
Some of the problems caused by smoking during pregnancy include:
- increased risk of premature birth
- increased risk of miscarriage and infant death
- lower birth weight – on average, about 150 to 200 grams less than normal
- up to three times the risk of SIDS.
Smoking and breastfeeding
Over two-thirds of females who quit when they are pregnant resume smoking after their babies are born. Although smoking and breastfeeding is not ideal, it is better than smoking and not breastfeeding. Stopping smoking during breastfeeding is very worthwhile.
Some of the problems caused by smoking while breastfeeding include:
- Some of the chemicals in cigarettes can pass from the mother to the baby through breastmilk.
- Smoking can reduce milk production.
- Women who smoke are less likely to breastfeed and are more likely to wean their children earlier than mothers who do not smoke.
Smoking during pregnancy can cause problems for the child in later life
Smoking during pregnancy can impair a child’s health for years to come. Health effects may include:
- weaker lungs
- higher risk of asthma
- low birth weight, which is linked to heart disease, type 2 diabetes and high blood pressure in adulthood
- increased risk of being overweight and obese in childhood.
Pregnancy and quitting smoking
Ideally, a pregnant woman should stop smoking. In reality, less than half of females quit when pregnancy is planned or confirmed. If you need help to quit, see your health professional for information and advice or call Quitline.
If you are finding it tough to stop smoking, don’t despair. There is evidence to suggest that stopping smoking by the fourth month of pregnancy can reduce some of the risks, such as low birth weight and premature birth.
Nicotine replacement therapy during pregnancy
It is recommended that you first try to quit without medication. However, if you are unable to quit, you may use nicotine replacement therapy (gum, lozenges, mouth spray, patches, or an inhalator) to help you. While using these products is considered safer than smoking, even this smaller amount of nicotine may not be entirely risk-free for your baby.
If you are pregnant, it is important to consult your doctor before using nicotine replacement therapy to discuss the risks and benefits of using it. Pregnant women should also seek assistance from the Quitline and its advisors for alternative quitting methods.
Where to get help
- Your doctor
- Obstetrician
- Quitline Tel. 13 7848 (13 QUIT)
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Last updated:
March 2017
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