Pregnancy and smoking

Smoking while pregnant exposes you and your unborn child to an increased risk of health problems. Passive smoking can also affect you and your unborn child. Australian studies showed that about 10 per cent of women smoked during pregnancy in 2016. 

If you smoke while pregnant you are at increased risk of a wide range of problems including miscarriage and premature labour, and you are twice as likely to give birth to a low-birth-weight baby compared to a mother who does not smoke. 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 you smoke during your pregnancy, the greater your risk of complications and having a low-birth-weight baby. However, there is no solid evidence that cutting down on the number or strength of cigarettes you smoke significantly reduces the risks to the fetus. Stopping smoking completely as early as possible is a much better option for the health of you and your baby.

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

If you are pregnant, every time you smoke a cigarette, it cuts down oxygen to your unborn baby and exposes them 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
• delayed 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 sudden unexpected death in infancy (SUDI).

Smoking and breastfeeding

Over two-thirds of women 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 you to your baby through your breastmilk.
• Smoking can reduce your 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 your child in later life

Smoking during pregnancy can impair your 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
• increased risk of attention deficit hyperactivity disorder (ADHD).

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. 

You can also call the Quitline (Tel. 13 7848). Quit Specialists will provide free support during your pregnancy and for some time after to help you remain a non-smoker. Aboriginal Quit Specialists are also available.

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, an inhalator, or 16-hour patches) 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. The Quit Specialists at the Quitline can help you decide what support is best for you.

Where to get help

• Your GP (doctor)
• Your obstetrician
• Quitline Tel. 13 7848 (13 QUIT)