Path: bloom-picayune.mit.edu!snorkelwacker.mit.edu!americast.com!americast.com!americast-post Newsgroups: americast.twt.news From: americast-post@AmeriCast.Com Organization: American Cybercasting Approved: americast-post@AmeriCast.com Subject: Nicotine byproduct harms human eggs Date: Sat, 14 Nov 92 16:22:11 EST Message-ID: \SE A;WORLD \SS (WS) \HD Nicotine byproduct harms human eggs \BY ASSOCIATED PRESS \DT LONDON LONDON (AP) - British scientists say a nicotine byproduct detected in human eggs may help explain why smoking appears to reduce a woman's fertility. The study not only shows that a breakdown product of nicotine - cotinine - seeps into eggs, but that women with cotinine-tainted eggs were dramatically less fertile. Previous studies suggested smokers have more difficulty getting pregnant than nonsmokers. "We are now closer to understanding how smoking impairs fertility," said Dr. Michael Hull, professor of reproductive medicine and surgery at Bristol University, who directed the study. "The practical message is that infertile or subfertile couples should really stop smoking," he said. The study is published in today's issue of the Lancet, a British medical journal. "This is terribly interesting because epidemiologists like me can often say what's going on in a big population, but it is not often we can say why," said Dr. Martin Vessey, a professor of social and community medicine at Oxford University. A study conducted by Dr. Vessey's team found that women who smoked had more trouble getting pregnant than nonsmokers. In Dr. Hull's new study, investigators examined eggs from 45 women undergoing in vitro, or "test tube," fertilization. The women produced roughly the same number of eggs, regardless of the presence of cotinine. However, the fertilization rate plummeted from 72 percent among those without cotinine to 44 percent among those with it. Among 32 women with no cotinine in their eggs, 84 of 116 eggs fertilized. Among 13 women with cotinine, 20 of 45 eggs fertilized. Thomas Lauria, a spokesman for the Tobacco Institute, said Thursday the institute could not comment because it had not seen the Lancet study. This article is copyright 1992 The Washington Times. Redistribution to other sites is not permitted except by arrangement with American Cybercasting Corporation. For more information, send-email to usa@AmeriCast.COM