Mothers who smoke any number of cigarettes – even one a day – during their pregnancy more than double their risk of seeing their infant die before their first birthday, according to new research published in Pediatrics.
Women smoking an average of between one and 20 cigarettes a day increase the odds by 0.07 with each cigarette smoked – but even women who smoked before their pregnancy saw an increased risk in their child dying from sudden unexpected infant death (SUID) – an unexplainable death of an otherwise healthy baby less than a year old.
To understand how SUID deaths relate to maternal cigarette use, researchers analyzed data collected by the Centers for Disease Control and Prevention on smoking habits in pregnant women who had given birth between 2007 and 2011. Of the 20 million live births collected in the data set, just over 19,000 were attributed to SUIDS or associated accidental suffocation or strangulation while asleep.
Women who cut back on smoking by the third semester saw a 12 percent decrease in risk, while those who successfully quit were associated with a 23 percent reduced risk. On the other hand, mothers who smoked three months before getting pregnant but quit in the first trimester still had a higher risk of SUID when compared to non-smokers.
"The most important takeaway is for women to understand that quitting smoking before and during pregnancy by far results in the greatest reduction in SUID risk," said lead study author Tatiana Anderson in a statement. "For pregnant women unable to quit entirely, every cigarette they can eliminate will reduce the odds of their child dying suddenly and unexpectedly from SUID."
Though the authors note their study is limited to “conservative smoking estimates” because their data set does not include environmental smoke exposure during pregnancy or postpartum, including fathers who smoke, they affirm that maternal smoking has been linked to premature deaths in infants. In fact, some studies have shown that smoking is the “strongest prenatal modifiable risk factor for SIDS in industrialized nations,” according to the study.
"With this information, doctors can better counsel pregnant women about their smoking habits, knowing that the number of cigarettes smoked daily during pregnancy significantly impacts the risk for SUID," said Anderson. "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 (SIDS) rates, we hope advising women about this risk will result in less babies dying from these tragic causes."