Smoking while pregnant is a bad idea. It leads to a higher chance of SIDS, ADHD, and obesity. It turns out it also means the child will have more difficulty quitting smoking should they start. According to Edward Levin, Ph.D., a professor of biological psychiatry at the Duke Center for Nicotine and Smoking Cessation Research and the lead study investigator, "Smoking during pregnancy can harm the baby in ways that extend far beyond preterm delivery or low birth weight. It causes changes in the brain development of the baby that can last a lifetime."

The research suggests that not only should pregnant women quit smoking, but that they should do it without the use of nicotine-based products such as patches or gum. In other words, mothers-to-be should quit cold turkey. "It is easy to quit smoking -- anyone can do it, for a brief time," Levin said. "But not taking it up again -- that is the part that has proven so difficult for most people, especially those who have been exposed to nicotine before birth."