HealthDay News — The risk for sudden unexpected infant death (SUID) is increased with any maternal smoking during pregnancy, according to a study published online March 11 in Pediatrics.

Tatiana M. Anderson, PhD, from the Seattle Children’s Research Institute, and colleagues analyzed the US Centers for Disease Control and Prevention Birth Cohort Linked Birth/Infant Death Data Set for 2007 to 2011, with data for 20,685,463 births and 19,127 SUIDs.

The researchers found that the risk for SUID more than doubled with any maternal smoking during pregnancy (adjusted odds ratio, 2.44) and increased twofold between no smoking and smoking 1 cigarette each day throughout pregnancy. The probability of SUID increased linearly for 1 to 20 cigarettes per day, with each additional cigarette smoked per day increasing the odds by 0.07 for one to 20 cigarettes; the correlation plateaued beyond 20 cigarettes. Compared with those who continued smoking, mothers who quit or reduced their smoking decreased their odds (reduced: adjusted odds ratio, 0.88; quit: adjusted odds ratio, 0.77). Assuming causality, maternal smoking during pregnancy could directly account for 22% of SUIDs.

“Educational efforts to decrease SUID risk should strongly encourage nonsmoking practices before pregnancy and smoking cessation during pregnancy,” the authors write. “We estimate that US SUID rates could be reduced by 22% if no women smoked during pregnancy.”

One author disclosed serving as a paid medical expert in a case of unexpected sudden infant death.

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