National Toxicology Program

Overview

The California Environmental Protection Agency (CAL/EPA) has identified tobacco smoke and nicotine, a chemical in tobacco smoke, as developmental toxins, which means that there is evidence that the substances are harmful to unborn children. Smoking by pregnant women limits the amount of nutrients and oxygen that reach the unborn child. Effects of smoking while pregnant may include miscarriages, still births, low infant birth weight, and sudden infant death syndrome. Children born to smoking mothers may also suffer more colds and other lung problems, and may have learning difficulties, and behavioral problems. The same type of problems can also occur if a pregnant woman does not smoke herself, but is around others who smoke. Babies exposed to cigarette smoke may experience more colds, lung problems, and ear infections. Woman should not smoke while breast feeding because the chemicals in cigarette smoke can enter the breast milk. Agencies such as the March of Dimes and American Lung Association® offer suggestions to help pregnant women stop smoking.

Health effects of smoking while pregnant

Tobacco smoke and nicotine, a chemical in tobacco smoke, are listed on the California EPA (CAL/EPA) Proposition 65 list of developmental toxins (Cal/EPA Proposition 65 List). This means that an expert group of scientists found sufficient evidence that the compounds can be harmful to unborn children.

According to the American Lung Association® (American Lung Association Date Extracted 1/21/99), "Smokers take in poisons such as nicotine and carbon monoxide (the same gas that comes out of a car's exhaust pipe). These poisons get into the placenta, which is the tissue that connects the mother and the baby before it is born. These poisons keep the unborn baby from getting the food and oxygen needed to grow. As a result babies of smokers are often smaller. The American Lung Association® (American Lung Association Date Extracted 1/21/99) has stated that underweight babies are "often sick with lots of health problems. Smaller babies are more likely to need special care and stay longer in the hospital. Some may die either at birth or within the first year." According to the March of Dimes, other problems associated with smoking during pregnancy include miscarriages, still births, and premature birth (March of Dimes, September 2006 ). The American Lung Association® has stated that (American Lung Association September 2000) "Smoking during pregnancy is estimated to account for 20 to 30 percent of low-birth weight babies, up to 14 percent of preterm deliveries, and some 10 percent of all infant deaths."

Some of the effects of smoking while pregnant may not be apparent at birth, but are seen as the child starts to develop. Smoking during pregnancy may be a cause of sudden infant death syndrome (crib death), a condition in which apparently healthy babies die suddenly while sleeping (March of Dimes, September 2006).  Additionally, maternal smoking during and after pregnancy has been linked to asthma in children (American Lung Association September 2000).  In addition, the children may have learning difficulties and behavioral problems (March of Dimes, September 2006).

Second hand smoke

Exposure to second hand smoke, also called involuntary smoking, occurs when non-smokers breath in the cigarette smoke from others around them. Second hand smoke is harmful to both pregnant women and infants. According to the American Lung Association® (American Lung Association Date Extracted 1/21/99), "New studies show that if a woman's partner smokes near her during her pregnancy, there are added risks. She has a greater chance of having a baby that weighs too little and may have health problems."

Smoking while breast feeding

According to the American Lung Association® (American Lung Association September 2000), women should not smoke while breast feeding because, "Breast milk often contains whatever is in the woman's body. If the woman smokes, the baby ingests the nicotine in her breast milk."

Tips to stop smoking

The American Lung Association® (American Lung Association Date Extracted 1/21/99) has stated, "The best time to quit is when the woman thinks she will get pregnant in the near future. If she does quit, her baby will probably weigh the same as the baby of a woman who has never smoked. Or if she quits within the first three or four months of her pregnancy she can lower her baby's chance of being born too small and with lots of health problems. Even if a woman quits at the end of her pregnancy, she can help her baby get more oxygen and have a better chance of making it. It's never too late to quit, but the earlier the better for both the mother and her baby!" According to the American Lung Association® (American Lung Association September 2000), "Reducing frequency of smoking may not benefit the baby. A pregnant woman who reduces her smoking pattern or switches to lower tar cigarettes may inhale more deeply or take more puffs to get the same amount of nicotine as before."

The following tips for helping a pregnant woman stop smoking were obtained from the March of Dimes (March of Dimes, September 2006):

• Write down why you want to stop smoking.
• Choose a "Quit Day" sometime in the next two weeks.
• Ask a nonsmoking "buddy," like your partner or a friend, to help you quit.
• Throw out all cigarettes, ash trays, matches and lighters on your "Quit Day."
• Stay away from places and activities that make you want to smoke.

When you feel like smoking, do one of these instead:  

• Brush your teeth.
• Go for a walk.
• Call a friend.
• Drink water or juice.
• Chew sugarless gum or eat carrot sticks.
• Take a deep breath and count to five. Let the air out slowly. Do this five times.
• Refer back to your list of reasons for quitting.
• Keep your hands busy. Find things to do with your hands so you can't hold a cigarette.
• Tell yourself, "I can quit smoking."

Agencies to contact for additional information

The following agencies can be contacted for more information about smoking and pregnancy or for help to quit smoking:

For a catalog of educational materials, brochures, information sheets, videos, and Spanish language materials, contact the March of Dimes Resource Center or e-mail publiceducation@modimes.org.

March of Dimes Birth Defects Foundation
National Office
1275 Mamaroneck Ave.
White Plains, New York 10605

Call Toll Free: 888-MODIMES (663-4637)

For more information on lung health programs, and special events, call your local American Lung Association at 1-800-LUNG-USA (1-800-586-4872)

Links to other useful information

Centers for Disease Control