'Snus' tobacco linked to stillbirth risk

Pregnant women who use a smokeless form of tobacco known as "snus" may have a risk of stillbirth on par with women who smoke cigarettes, a large study of Swedish women suggests.

The findings, say experts, should serve as a warning to women who are or may become pregnant that snus is not a "safe" alternative to cigarettes.

Snus, also called moist snuff, is different from other smokeless tobacco products because it is "spitless" and has lower levels of toxins called tobacco-specific nitrosamines.

Snus is generally thought to be less harmful than cigarettes as far as the risks of heart disease and cancer, and the product has been advocated as a "socially acceptable" way for smokers to get their nicotine fix - and as a way to help them cut down on cigarettes.

Snus originated in Sweden and is still mainly used there. But in the past few years tobacco makers have been test-marketing their own snus products based on the traditional Swedish one. Brands such as Camel Snus and Marlboro Snus are now available in the U.S.

Smoking during pregnancy is well-known to carry risks, including elevated odds of miscarriage, low birth weight and stillbirth.

Much less has been known about the potential harms of using snus during pregnancy. But a study published earlier this year by the research group behind the new study found that women who used snus during pregnancy had a higher risk of preterm delivery than those who used no tobacco products.

For the current study, published in the journal Epidemiology, the Swedish team used a national birth register with information on nearly 611,000 women who were pregnant between 1999 and 2006. Of these, 58,502 were tobacco smokers and 7,629 used snus.

Overall, 1,926 of the women in the register - or about 0.3 percent - had a stillbirth. (Stillbirth generally refers to a pregnancy loss after the 20th week; but in this database, it was defined as a pregnancy loss after at the 28th week or later.)

The study found that women who reported using snus during pregnancy had a 60 percent higher risk of suffering a stillbirth than women who used no tobacco products. The risk was 40 percent higher for light smokers, and for heavy smokers it was more than double that of non-users of tobacco.

Among the women who reported using snus, 0.5 percent (40 women) suffered a stillbirth; that compared with just under 0.3 percent (1,386 women out of more than 500,000) of those who used no tobacco products during pregnancy.

Of the 41,488 women considered light smokers - nine or fewer cigarettes per day - 0.4 percent (172) had a stillbirth. And among the 17,000 women who smoked more heavily, the stillbirth rate was 0.7 percent (120).

Although snus may appeal to pregnant women who are trying to avoid cigarettes, "using moist snuff is not a safe way to quit smoking when you are pregnant," lead researcher Dr. Anna-Karin Wikstrom, of Karolinska University Hospital Solna in Sweden, told Reuters Health in an e-mail.