If you're pregnant, exposure to secondhand cigarette smoke may cause just as much damage to your baby as if you smoked yourself, new study shows.

August 24, 2005 -- Most women have heard the message for years: If you are pregnant, you should not smoke cigarettes. But now a new report shows that smoking cigarettes and being exposed to secondhand smoke during pregnancy are equally likely to cause permanent genetic mutations in the fetus.

The report, published in a recent issue of BMC Pediatrics, found that there were similar and significant increases in gene mutations among babies born to active smokers, to women who were exposed to secondary smoke during pregnancy, and to women who quit smoking when they found out they were pregnant. The gene mutations were measured by examining umbilical cord blood.

The study's authors hypothesized that a woman who quits smoking when she finds out that she is pregnant is more likely to be exposed to second-hand smoke by socializing with friends and family who smoke, or by continuing to go to places where others smoke.

"If passive exposure does as much damage to the fetus as active smoking, it is imperative that workplace protection be offered to pregnant women, or better, to women who might or intend to become pregnant," the study's authors wrote. "This protection must also be provided in the home, where not only the mother, but any other smoking members of the household should be encouraged to quit for the duration of the pregnancy (or longer), or at least should not smoke in the presence of the pregnant woman."

A pregnant mom's tobacco smoking has long been associated with premature delivery, low birth weight, deficient lung and neurological function, and increased risk of perinatal mortality. The longer the woman smokes during pregnancy, the greater the effect on the infant's birth weight, according to the Centers for Disease Control and Prevention (CDC).

What do you think of this study? If you were pregnant, how did you feel when smokers were around? Should workplaces have to offer protection to pregnant women and women who intend to get pregnant? What about in the home? Should spouses, family and friends stop smoking during a woman's pregnancy, too? Share your thoughts on our message board below:

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