Smoking affects fertility—study

Press, 1 June 1985, Page 16

Smoking affects fertility—study

NZPA-Reuter Chicago A team of scientists has added another possible hazard — impaired fertility in women — to the long list of health problems linked to cigarette smoking. Researchers said a study of 678 women indicated that those who smoked cigarettes had only 72 per cent of the "per-cycle” pregnancy rate of non-smokers. The effect appeared most pronounced among heavy smokers, they said. - The study by scientists at the National Institute of Environmental Health Sciences, described as the first of its type, surveyed pregnant women in the Minneapolis-St Paul area during 1983. The study compared the time it took smokers and non-smokers to conceive after they had stopped using birth control. Smokers were “3.4 times more likely to have taken

greater than a year to conceive compared with non-smokers,” it found. Also, women who smoked more than 20 cigarettes a day had only 57 per cent of the per-cycle pregnancy rate of non-smokers. The study said the smoking habits of the women’s husbands did not appear to affect the fertility of the women. “These data provide evidence that reduced fertility should be added to the growing list of reproductive hazards of cigarette smoking,” the researchers said. Women are already routinely warned not to smoke during pregnancy. Smoking has been linked since 1950 to lung cancer and has been identified in other research as a possible contributor to heart and circulatory problems. The study on smoking, published in the current issue of the “American Medical Association Jour-

nal,” said the mechanism by which smoking affects fertility was not known. It could involve interference with the development of the egg, or interference with the process by which the egg becomes fertilised, it said. “The effect of a toxin that impairs fertility might range from transient, localised disruption of uterine function, to mutagenic damage to the gamete (egg cell),’’ the study said. “Thus, an impairment is not only a concern in terms of the time it takes a couple to conceive, but also a warning signal of possible long-term damage,” it added. The researchers said some women in the study who had stopped smoking within a year prior to conceiving had apparently returned to normal fertility, but the size of the sample was not sufficient to draw a general conclusion on this point.