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Second-Hand Smoke and Smoking During Pregnancy

What is environmental tobacco smoke (ETS), or second-hand smoke?
Environmental tobacco smoke (also called ETS or secondhand smoke) is the smoke you breathe that comes from other people, whether they exhale it or get it from the tobacco burning near you, like the end of a cigarette (sidestream smoke). 

ETS or secondhand smoke has over 250 dangerous chemicals in it.  These dangerous chemicals include toxins (poisons) and carcinogens (cancer-causing chemicals).  Some of these harmful chemicals are:

According to the U.S. Environmental Protection Agency (EPA)[1] and the National Institutes of Health (NIH)[2], secondhand smoke is a known cause of cancer in humans.

How does secondhand smoke affect babies? Infants and toddlers have tiny bodies, tiny lungs, and breathe rapidly.  All of these things increase how smoke can affect them.  "The EPA estimates that passive smoking is responsible for between 150,000 and 300,000 lower respiratory tract infections in infants and children under 18 months of age annually, resulting in between 7,500 and 15,000 hospitalizations each year."[3]

Some major risks for babies from ETS are:

How does secondhand smoke affect kids?
Exposure to environmental tobacco smoke (ETS) puts children at risk for serious health problems.  Breathing in second-hand smoke  is also called “involuntary smoking” or “passive smoking”). Can you imagine giving a cigarette to your two-year-old?  The exposures to secondhand smoke can affect children in very similar ways.

There are many ways in which children are hurt by secondhand smoke.  Smoking around kids puts them at risk for:

Exposure to environmental smoke increases kids’ risk later in life of:

How can I protect my children from secondhand smoke?
Many people believe that ETS won’t be too bad for their kids if they smoke with the window cracked open at home or in the car, or use an air filter or fan.  This is not correct.  In fact, the Surgeon General says there is no amount of contact with secondhand smoke that is risk-free[4].  Many of the harmful substances in secondhand smoke stay in your clothes and the air and in furniture, carpets and curtains of your house or car long after you’ve put out the cigarette, cigar or pipe.

For more information on protecting kids from secondhand smoke:

What if my child has asthma?

Kids with asthma especially need clean air to breathe.  They can stay healthier if the air around them doesn’t increase their risk for asthma attacks.  Secondhand smoke can trigger asthma attacks. 

What are the dangers for kids with sickle cell disease?
Kids with sickle cell disease who are exposed to ETS at home have more than twice as many episodes of pain (known as "crises") as sickle cell patients who were not exposed. Sickle cell crises involve serious symptoms, and often require hospitalization. Researchers in one study estimate that ETS exposure increases the risk of crisis by 90% among children with sickle cell disease. [5]

How can I prevent my kids from smoking if I smoke?
Parents can be the biggest influence in their kids’ lives when they stay involved.  Ideally, you would quit using tobacco to send your kids the right message.  If that’s not an option for you right now, then make sure you talk to your kids honestly and often about tobacco use. Start talking around age 5 or 6, and keep it up.  Many kids are addicted by age 14.  Don’t use tobacco around your kids, don’t offer it to them, and don’t leave it where they can easily get it.  It is possible to help keep your kids tobacco-free even if you smoke[6] [7]

What about smoking during pregnancy?

Women who smoke during pregnancy are at risk for the following:

Cigarette smoking delivers thousands of chemicals to an unborn baby, some of which are well-documented reproductive toxins—like lead, for example.  Other chemicals that can affect a developing fetus are nicotine and carbon monoxide[9]. Nicotine narrows blood vessels and crosses the placenta.  It reduces blood flow to the uterus and placenta.  Carbon monoxide prevents the blood from being able to carry oxygen, and can lead to the fetus not getting enough oxygen. 

Researchers have found many different abnormalities at the microscopic level in placentas, fetuses, and newborns of women who smoked while pregnant.Smoking during pregnancy has been linked to 10 percent of all infant deaths [10].  It is the main risk factor contributing to Sudden Infant Death Syndrome (SIDS) [11] [12]. Being exposed to mom’s cigarette smoking during pregnancy is a risk factor after birth for wheezing and asthma in children up to two years old [13].  Smoking during pregnancy may also be a risk factor for preterm birth.[14]

 In a review of the research evidence on prenatal tobacco exposure and development problems [15] , the author says that prenatal exposure to tobacco seems to affect newborn neurological development and behavior.  In studies of animals exposed in utero to carbon monoxide and nicotine, these toxins harmed thinking and behavior. Smoking during pregnancy may also cause the brain and nervous system of the human fetus to develop abnormally.

Smoking early on and through pregnancy is linked to worse pregnancy outcomes. You can avoid some of the harmful effects by cutting back on smoking, but not smoking at all is even better for your baby. [16]

Talk to your doctor about quitting smoking or cutting back while pregnant.  Nicotine replacement therapy may be an option [17].

How can I get help quitting smoking?
Never give up on quitting.  Here are some resources to help you:

Where can I find more information?

What are some organizations and governmental agencies that address second-hand smoke and tobacco use?


Written and compiled by Kyla Boyse, R.N.  Reviewed by Steven E. Gay, MD, MS.

Updated October 2008

U-M Health System Related Sites
U-M Pediatrics

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