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Published: 2019-10-16 11:00 | Updated: 2019-10-18 13:25

Children exposed to Swedish snus during pregnancy have higher blood pressure

Photo: iStock

Children are more likely to have higher systolic blood pressure by age six if their mom used the Swedish powdered tobacco product snus during pregnancy. This according to a new study by researchers at Karolinska Institutet published in the Journal of the American Heart Association.

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Felicia Nordenstam. Photo: Niclas Grunewald

“Tobacco products of any type should be avoided during pregnancy. Nicotine easily passes through the placenta and reaches the developing fetus and may have a negative impact on the future health of the child,” says lead author Felicia Nordenstam, researcher at the Department of Women’s and Children’s Health, Karolinska Institutet and pediatric cardiologist at Karolinska University Hospital in Stockholm, Sweden.

Can become clinically significant

The researchers measured blood pressure and heart rate in 21 children, five to six years of age, whose mothers used snus during pregnancy and 19 children of similar ages whose mothers used no tobacco products. They found that the systolic blood pressure in snus-exposed children was 4.2 mmHg higher than in children with no nicotine exposure.

“Although the increase in blood pressure is not clinically significant for an individual child, it may increase more quickly to a point of clinical significance during adulthood, especially if paired with other risk factors such as obesity or inactivity,” says Felicia Nordenstam.

The researchers also found that the heart rate variability was higher among exposed children. How the increase in heart rate variability and blood pressure affects cardiovascular health in adulthood remains to be explored.

Many studies on smoking

Previous studies of women who smoke during pregnancy have consistently found adverse effects, including preterm birth, low birth weight and still birth, as well as higher blood pressure among exposed children. However, those studies could not separate the effect of nicotine from the effect of other smoking-related by-products and could not control for second-hand smoke exposure after birth. The current study isolated nicotine exposure by studying women who used only Swedish snus, a moist powdered tobacco product placed between the gums and upper lip.

The research was supported by the Swedish Research Council, the Swedish Research Council for Health, Working Life and Welfare, the Samaritan Foundation, Odd Fellows Grand Lodge Sweden and the Childhood Foundation of the Swedish Order of Freemasons.

This news article is based on a press release from the American Heart Association.

Publication

“Blood pressure and heart rate variability in preschool children exposed to smokeless tobacco in fetal life”. Felicia Nordenstam, Mikael Norman och Ronny Wickström. Journal of the American Heart Association, online 16 October 2019, doi:10.1161/JAHA.119.012629.

Editorial in the same issue of JAHA"Maternal Use of Snus in Pregnancy and Early Childhood Blood Pressure: A Warning for e‐Cigarettes?"