A new study finds dire statistics for women who smoke while pregnant: Even one cigarette a day doubles your baby's risk of sudden unexpected infant death. SUID is defined as any death of an infant under 1 year of age from sudden infant death syndrome (SIDS), accidental suffocation or strangulation, or any other ill-defined or unknown cause. After the first cigarette per day, the study found the risk of SUID increased by 0.07 for each additional cigarette smoked up to 20 per day, at which point it plateaued—and at which point it's triple the risk of women who don't smoke, the Seattle Times reports. Of the 3,700 SUID deaths in the US per year, researchers believe 800 could be prevented if no pregnant women smoked, per a press release. The study analyzed CDC data on 20 million babies to come to its conclusions.
"Similar to public health campaigns that educated parents about the importance of infant sleep position, leading to a 50% decrease in sudden infant death syndrome rates, we hope advising women about this risk will result in [fewer] babies dying from these tragic causes," says lead author Tatiana Anderson. The study found that women who reduced their smoking by the third trimester had a 12% decrease in SUID risk, while those who quit had a 23% decrease in risk. But it also found mothers who smoked three months before getting pregnant had a higher risk of SUID than nonsmokers, even if they quit in the first trimester. The study is the first to come out of a partnership between Seattle Children's Research Institute and Microsoft; a member of the team that worked on the study lost his son to SIDS in 2003. The Times explains that Microsoft "hopes to use its computing power to help address more of the world's confounding problems." (The dangers aren't limited to mothers who smoke.)