There is no such thing as a safe when it comes to smoking – especially if you are pregnant, a new study reveals.

According to a new US study, published earlier this week in the Journal Pediatrics, smoking even one cigarette a day during pregnancy can double the chance of sudden unexpected death for your baby. The new study analyzed data on smoking during pregnancy from the US Centers for Disease Control and Prevention's birth/infant death data set between 2007 and 2011. Over 20 million births, including over 19,000 unexpected infant deaths, where studied, and what the researchers found, was that the risk of death rises by .07 for each additional cigarette smoked, up to 20 a day, a typical pack of cigarettes. Disturbingly, by the time you smoke a pack a day, the study found, your baby's risk of unexpected sudden death has nearly tripled compared with infants of nonsmokers. "One of the most compelling and most important points that I would take away from the study is that even smoking one or two cigarettes still had an effect on sudden infant death," pulmonologist Dr. Cedric "Jamie" Rutland, a national spokesman for the American Lung Association told CNN. And while ending a smoking habit should ideally be the goal, of course, the study did find that even cutting back on the number of cigarettes was somewhat beneficial, with women who reduced their smoking by the third trimester saw a 12 percent decrease in sudden death risk; and quitting entirely by the third trimester created a 23 percent reduction in risk. "Every cigarette counts," said lead study author Tatiana Anderson, a neuroscientist at the Seattle Children's Research Institute. "And doctors should be having these conversations with their patients and saying, 'Look, you should quit. That's your best odds for decreasing sudden infant death. But if you can't, every cigarette that you can reduce does help.' "