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Second-Hand Smoke and Pregnancy Risk

From: C-reuters@clari.net (Reuters)
Subject: Tobacco smoke risky to babies of moms older than 30
Organization: Copyright 1997 by Reuters
Date: Wed, 9 Jul 1997 12:21:35 PDT

The study, in the July issue of ``American Journal of Epidemiology,'' said hundreds of thousands of pregnancies a year in the United States may be affected by second-hand smoke.

``Given the proportions of older women giving birth in the United States and adult exposure to ETS (environmental tobacco smoke), it is possible that upwards of 300,000 pregnancies among non-smokers could be affected by ETS exposure, which has implications for the family and for the child's long-term growth and development,'' the study said.

The study was conducted by researchers at the federal Centers for Disease Control who analyzed data collected from more than 17,000 low-income women in Arizona and North Dakota.

It found that non-smoking women older than 30 who lived with a smoker had a much greater chance of delivering a premature or underweight baby than did non-smokers of the same age group who lived in a smoke-free home.

Babies born to the older non-smoking women who were exposed to second-hand smoke weighed 90 grams (3.15 ounces) less on average at birth than babies born in smoke-free homes.

Birth weight is regarded as one indicator of overall infant health and development.

Links between second-hand smoke and pregnancy risks were weaker or absent among younger women or women who smoked, although older smokers exposed to second-hand smoke appeared to have greater risk of underweight babies than younger women in the same category.

There also was little difference noted in the weight of babies or the rate of premature births for women under 30 who did not smoke, regardless of whether they were exposed to second-hand smoke.

The study said factors behind the increased risk for older women could include the affect of airborne tobacco smoke on their placentas, which often work with less efficiency than those of younger women.

The article said factors unrelated to tobacco exposure may have affected the results. These include the accuracy of the women's reports of exposure to second-hand smoke, and certain social and economic factors.