Maternal smoking is one of the most important preventable risk factors for infant morbidity and mortality and is associated with an increased risk of Sudden Infant Death Syndrome (SIDS). SIDS is a cause assigned to infant deaths that cannot be explained after a thorough case investigation, including an autopsy, a scene investigation, and a review of clinical history.
A new study from Karolinska Institutet determined whether non-combustible nicotine use in pregnancy is associated with an elevated risk of SIDS. Scientists also studied how cessation before the antenatal booking influenced these risks.
The study found that mothers who used snus (a moist oral tobacco product) run three times the risk of sudden infant death during pregnancy. The risk was significantly reduced if the woman gave up snus before the first antenatal appointment. All nicotine products should be avoided during pregnancy, the scientists say.
Little study has been done on snus and other nicotine products, despite the fact that it is well-recognized that smoking during pregnancy increases the risk of abrupt infant death. To address this, the scientists conducted a registry analysis including more than two million infants born in Sweden between 1999 and 2019. During this time, only two out of 10,000 babies suffered sudden infant death, which is when death occurs suddenly for no apparent reason during sleep.
Scientists noted, “When registering for maternal care, just over one percent of the mothers took snus, and seven percent smoked—taking snus while pregnant was associated with a 70 percent increase in the risk of infant death during the first year, regardless of cause, and a three-fold increase in the risk of sudden infant death. The risks associated with snus were comparable to moderate smoking (one to nine daily cigarettes). The highest risks were associated with smoking over ten cigarettes a day.”
Anna Gunnerbeck, a pediatrician at the Astrid Lindgren Children’s Hospital and researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, said, “Given the dramatic rise in the use of snus among young women of fertile age in Sweden over the past few years and the growing popularity of e-cigarettes, women need to be informed of the potential risk to fetuses and infants. Our study indicates that nicotine is a risk factor for sudden infant death, so we conclude that all nicotine products should be avoided during pregnancy.”
The scientists were able to account for various significant possible risk factors for sudden infant death, including socioeconomic status and the mother’s age, by linking multiple registries. However, because unidentified factors could have influenced the findings, the scientists cannot establish any causal correlations.