Q&A: The Facts About Smoking and Pregnancy

Mothers-to-be would quit smoking if they could, but smoking remains an addiction, a serious chemical dependency that is difficult to stop whether or not a person is pregnant, experts say.

Answering questions about the issue is Paul Cinciripini, Ph.D., a professor in M. D. Anderson's Department of Behavioral Science and principal investigator on "Project Baby Steps," a smoking cessation study for pregnant women.

What makes smoking addictive?

All drugs, including nicotine, have an effect on certain areas of the brain that respond to reward and pleasure. People who use cocaine, alcohol and heroin do it because it feels good. With cocaine, people become euphoric. With alcohol, people also feel pleasure and report stress reduction.

Nicotine doesn't have those incredibly sharp effects. Nicotine provides subtle effects on brain neurochemistry. Smoking is something you can do all day long without euphoria or intoxication.

How is the addiction different for some pregnant women?

We don't know everything there is to know about smoking and pregnancy, but there are two things that seem to stand out among pregnant women who don't quit when they learn they're pregnant. They appear to be much more dependent on nicotine and might have a higher level of emotional impairment.

Many pregnant smokers have enormous trouble in living - poverty and abusive relationships, for example - so much so that we are studying that very carefully.

How do you address those problems to help smokers quit?

Baby Steps counselors address these types of issues by helping them recognize their emotions and channel that into something that is productive in getting what they want out of their situation. We help women get clarity about their lives and offer them a path.

What makes the study unique?

We've known for a very long time that people who don't quit on their own are much more likely to have these problems of living. The majority of studies that treat pregnant women are based on a public health model that provides very brief counseling and treats them in the same way that you'd treat women with a great deal of psychological resources.

We're saying that this is inadequate for many pregnant smokers. Our treatment focuses a great deal more time and attention on a woman's psychological well-being than any other treatment that she is likely to receive.

What percentage of pregnant women smoke?

The rate of smoking among women of childbearing age is not very high in our study populations. It's probably 14% or less. But statistics are much higher in women who have less than a high school education and who come from lower economic status. It's probably 25% within this group.

What are the side effects of smoking while pregnant?

Harmful effects of smoking during pregnancy have been documented in previous studies by the U.S. Department of Health and Human Services (HHS).

Those studies showed that smoking during pregnancy:

• Prevents up to 25% of oxygen from reaching the placenta
• Accounts for 20% to 30% of low-birth weight babies
• Accounts for up to 14% of pre-term deliveries
• Is responsible for approximately 10% of all infant deaths
• Raises the risk of miscarriage
• Increases risk of babies having weaker immune systems

Another consequence of smoking during pregnancy is the possibility of higher medical costs if babies have any problems after delivery. It can cost $30,000 to keep a baby in a neonatal unit for a week.

What are the statistics for relapse?

Relapse rates among women who quit smoking during pregnancy are high, with this percentage of women returning to smoking:

• 45% after two to three months
• 60% to 70% after six months
• 80% after one year

These high relapse rates are surprising because they occur in a population where the majority of women are smoke-free for seven to nine months prior to giving birth.

Has progress been made in smoking cessation programs?

We've made a lot of strides in drug development for smoking cessation and fewer innovations in behavioral treatments. The kinds of studies that we're conducting now are taking behavioral treatments to another level.