Tobacco and Pre and Post Natal Risks

Tobacco smoke exposure during pregnancy can cause many complications for the mother and baby.^{Footnote 1}
Read about second-hand smoke exposure during pregnancy.

• Key facts about tobacco use and pre and post natal risks
• How does tobacco use increase the risk of complications during pregnancy?
• How does tobacco use increase the risk of harmful delivery and neonatal outcomes?
• How does quitting reduce pre and post natal risks?
• Health benefits of quitting tobacco use at any age
• Call for free help to quit

Key facts about tobacco use and pre and post natal risks

• Toxic chemicals from tobacco smoke pass from the mother to the baby through the placenta.^{Footnote 2}
• Mothers who smoke or are exposed to tobacco smoke during pregnancy have a greater risk of preterm delivery and placental complications.^{Footnote 1Footnote 3}
• Nicotine, the drug in tobacco that causes addiction, can impact the unborn baby's growing brain and lungs.^{Footnote 4Footnote 5}
• Babies born to mothers who smoked during pregnancy may have low birth weight (under 2.5 kg or 5.5 lb).^{Footnote 1} Low birth weight increases the baby's future risk of illness and premature death.^{Footnote 1Footnote 6}
• Infants exposed to tobacco smoke during and after pregnancy have an increased risk of sudden infant death syndrome (SIDS). ^{Footnote 1Footnote 5Footnote 7}

View health-related messages for all tobacco product packaging.

How does tobacco use increase the risk of complications during pregnancy?

Pregnancy is the period a baby develops inside a uterus (womb) from conception to birth.

In 2021, 5% of Canadian women aged 15-55 who were pregnant in the past five years smoked while they were pregnant.^{Footnote 8}
Tobacco smoke contains many harmful chemicals that can pass from the mother to the baby through the placenta.^{Footnote 2}
The placenta (a blood-rich organ that grows in the uterus during pregnancy) provides nutrients and oxygen from the mother's blood to the baby through the umbilical cord.

Tobacco smoke can damage the placenta and increase the risk of the complete or partial separation of the placenta from the uterus wall (placental abruption) or the complete or partial covering of the cervical opening by the placenta (placenta previa). Both conditions put the mother and baby at a risk that may require emergency intervention.^{Footnote 1Footnote 2}

Carbon monoxide, an abundant toxin found in tobacco smoke, can harm the central nervous system and slow the baby's growth.^{Footnote 3Footnote 4} Nicotine can decrease blood flow through the placenta, depriving the baby of oxygen and nutrients.^{Footnote 4} Exposure to nicotine can also harm the baby's developing lungs and brain.^{Footnote 4Footnote 5}

How does tobacco use increase the risk of harmful delivery and neonatal outcomes?

A full-term pregnancy lasts 37 weeks or more. Babies born full term have the best chance of being healthy because the brain and lungs continue to develop in the last few weeks of pregnancy.^{Footnote 4Footnote 9}

Mothers who smoke or are exposed to tobacco smoke during pregnancy increases the risk for preterm delivery and a low birth weight baby (under 2.5 kg or 5.5 lbs at birth). Both conditions can increase the risk of illness and death for the baby.^{Footnote 1}

Exposure to tobacco smoke during and after pregnancy increases a baby's risk of sudden infant death syndrome (SIDS),^{Footnote 1Footnote 7} the sudden and unexplained death, during sleep, of an infant younger than one year of age.^{Footnote 1}

How does quitting reduce pre and post natal risks?

Quitting smoking before conception or early in pregnancy will produce the greatest benefits to the baby and expectant mother. However, quitting at any point during pregnancy also provides significant health benefits for both.^{Footnote 10}

Quitting during pregnancy reduces the effect of tobacco smoke on the baby's growth and lowers the risk of giving birth to a baby who is smaller than usual.^{Footnote 10}

Health benefits of quitting tobacco use at any age

Quitting tobacco use reduces the risk of premature death, improves health, and enhances quality of life.^{Footnote 10} Quitting at any age is beneficial to one's health.^{Footnote 10} Even people who have smoked or used tobacco heavily for many years benefit from it.^{Footnote 1Footnote 10} Quitting is the most important thing someone who smokes can do to improve their health.

Read more about the benefits of quitting smoking.

Call for free help to quit

Call the toll-free pan-Canadian quit line at 1-866-366-3667. Quit line counselling, alone or in combination with cessation medications, increases success in quitting.^{Footnote 10}