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FACT OR FANCY The Tobacco Institute May 1978

FACT OR FANCY? • Smoking causes wrinkles in women • Smoking causes low-weight babies • Women who smoke harm their babies before and after birth • Women are smoking like men and dying like men Of course you've noticed. It's difficult not to. Women are now the special target of those who would stamp out smoking. Since their usual, unsubstantiated charges have failed, these crusaders are now trying to hit women where they think them to be most vulnerable -- with threats to their babies and their good looks, and, yes, even their sex lives. In the belief that full, free and informed discussion of the smoking controversy is in the public interest, The Tobacco Institute has assembled the most frequently heard allegations concerning women and smoking -- and created a dialogue encom- passing the current scientific knowledge on each point. Here, then, are some questions about women and smoking -- and the answers, at least where they are known. I

I -2- CONTENTS Page Smoking Women 3 Small Babies 5 Pregnancy Outcome 9 ~ ~ Effects on Children 13 Sex and Reproduction 15 Facial Wrinkles 17 Advertising 19 Ulcers 21 Lung Cancer 23 Heart and Vascular Disease 29 Chronic Respiratory Disease 39 Increased Morbidity 41 Summary 43 Reference Sources 45

-3- 0. First of all, is it true that more women are smoking today than ever before? The number of adult American women who choose to smoke is apparently larger than ever. But so is the number of women in the U.S. population. The incidence of smoking among women -- the rate, or percentage of women who smoke -- is, however, as low as it was before World War II, when women first began smoking in significant numbers. Public surveys over the last 40 years show,an increase from 1935 to 1944, when more than four out of 10 women said they smoked, and a gradual drop to the less than three out of 10 estimated by the Public Health Service in 1975 (34, 36-38, 99, 100, 111). The question of the amount of smoking is much more difficult to resolve because there is the known tendency of persons to underestimate the number of cigarettes smoked daily. However, in commenting on a 1975 survey of adult smoking, a consulting psychologist who has directed government smoking surveys since 1967 stated last year in reference to women's smoking levels during the last decade, "No, they're not smoking more cigarettes" (40). Some persons who disapprove of cigarette smoking say that the larger number of women smoking today accounts for everything from higher lung cancer death rates to an allegedly higher incidence of ulcers, not to mention smaller babies and even larger government disability costs for emphysema. But if the percent of women in the general population who smoke is not larger, and if women smokers are not smoking more, then any higher incidence of disease cannot logically be attributed to cigarettes.

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-5- Do women who smoke while they're pregnant have smaller babies? Q. Yes, their babies usually weigh less than the babies of mothers who don't smoke (105). Detractors of smoking emphasize the reduced weight of smokers' babies because, they say, birth weight is one of the most important predictors of risk in infancy. And because smokers have smaller newborns whatever the cause -- they are more likely than nonsmokers to bear infants that are low-birth-weight (LBW), an arbitrarily set measure of below 2501 grams (about 5.5 pounds) (113). "It is now generally accepted that maternal smoking is related to a reduction in birth weight," National Institutes of Health researcher Debra Silverman wrote in the June 1977 American Journal of Epidemiology (90). She said: The critical issue is whether smoking causes a reduction in birth weight (the causal hypothesis) or whether smokers are a self-selected group that differs from nonsmokers in ways unrelated to smoking, including the production of lower weight babies (the self-selection hypothesis). Some other differences among women which are associated with varying birth weights of their children, or outcomes of their pregnancies -- but do not necessarily cause those variations -- are socioeconomic level, race,age, height, previous obstetric experience and access to adequate health care. A baby's sex and whether it is a first or, say, fifth child can also affect weight (13). To control for as many of these differences as possible, Silverman decided to look at weight differences in pairs of infants born to the same

-6- mother. And she located 1016 such pairs, one third of them born to women who had begun smoking sometime after their first pregnancies. Silverman reasoned that if smoking alone causes birth-weight reduction, the mean weight differences between first and second babies of mothers who smoked only during the second pregnancy would be signi- ficantly greater when compared to those observed where mothers smoked in both pregnancies, or neither. And the second babies of the "changed smokers" would be lighter than the first. Neither supposition proved true. There were all the expected differences -- smokers generally had lighter babies than nonsmokers and the "changed smokers" produced babies with weights between smokers and nonsmokers. But the differences were not large enough to establish that they could not have occurred by chance. Strangely enough, the babies born to smoking mothers who had not smoked in the previous pregnancy were slightly heavier on the average than their older brothers and sisters had been. But this was thought to have occurred because of the youth of these mothers when they bore their first children. Young mothers produce small babies. Silverman claimed her study failed to confirm that infant weight is dependent on innate characteristics of the mother rather than any effect of smoking. But she said the observation that future smokers before they began smoking tended to have lighter infants than nonsmokers was "more consistent with the self-selection hypothesis" (90). O W %3 0 Her findings were consistent with two other studies indicating that W C11 W some women will have smaller babies whether or not they smoke in pregnancy. W

-7- One, a large California project, included women who began smoking after delivering their first children. Those children, born before the mother smoked, were lighter than the nonsmokers' infants in the study (119). The other study, done in Scotland, reported that sisters of women who delivered low-weight infants also tended to have lighter babies (57). At least one large-scale study -- of British births in one week in 1958 -- indicated that smoking mothers have heavier babies if they quit or cut down on smoking after the fourth month (14). More recent research, published in 1977, suggests that any fetal weight reduction attributed to smoking does not occur in the later months -- if indeed it is caused by smoking. Studying more than 1000 pregnant women registered with three maternity units, a British researcher found no statistically significant weight difference between the babies of smoking mothers who quit early in pregnancy and those who had quit but resumed smoking in the last four months (26). What little difference there was -- an average of 2.8 ounces less -- was, he said, in the opposite direction to that which would be expected if smoking in late pregnancy reduced the birth weight. The researcher also found that there was no proportional decrease in birth weight with increasing amount smoked by the mother and he said this appeared to support what he called "the other-factor hypothesis." LBW infants are not necessarily premature (born too soon). They are small for their gestational age and are the subject of concern because their risk of death is almost 10 times greater than that of infants in the Q CJ next highest weight category, 20 times greater than infants of the most ~ W common birth weight category (113). w ~j1

-8- What opponents of smoking fail to point out, however, is that almost all the research on the subject has shown that the LBW babies of women who smoke in pregnancy are healthier than the LBW infants of women who have not smoked. The 1973 Public Health Service report, "The Health Consequences of Smoking," says: If mortality rates were compared for those infants of smokers and nonsmokers weighing less than 2500 grams, the infants of nonsmokers apparently had a considerably higher risk than did those of smokers (105). (Emphasis added.) 0

-9- Q, Then why the slogan that pregnant women who smoke endanger two lives? A. Who knows -- perhaps because so many well-meaning persons who nowadays seem to want to improve the lives of others accept old myths. But propaganda based on such ignorance can only delay scientific progress. Some studies have shown a higher rate of spontaneous abortion, stillbirth and infant deaths among smoking women (13,22,35,66). Other studies, however, have shown no differences at all (27, 77, 80, 87, 98, 118). But the conflict in evidence is not considered by those who dis- approve of smoking. And they ignore the paradox that the U.S. infant mortality rate continues to drop (101) while the denigrators of cigarettes claim that more women than ever -- and presumably many mothers-to-be -- are smoking. Nor do the anti-smoking tracts and speakers cite other factors that may affect the unborn child. Even a partial listing would have to include occupational exposures, viruses, X-rays, interval between pregnancies, both obesity and insufficient weight gain by the mother, use of hormones, aspirin, antibiotics, vitamins -- and, of course, illicit drugs (12, 21, 49). One of the most recently identified factors is the proximity to airports, unbelievable as it appears (7).