Paternal and Maternal Smoking Habits before Conception and During the First Trimester: Relation to Spontaneous Abortion

PURPOSE: This study examined the association between maternal smoking before and during the first trimester of pregnancy and spontaneous abortion.

METHODS: We have been conducting a hospital-based case-control study on risk factors for spontaneous abortion in the greater Milan area. We collected information from 782 cases of spontaneous abortions and 1543 controls (women who delivered at term healthy infants).

RESULTS: With respect to never smokers, the odds ratio (OR) were 0.7 (95%, confidence interval (CI), 0.5–1.0) for women who quit smoking and 1.3 (95% CI, 1.0–1.6) for those who continued during pregnancy. Women who smoked more than 10 cigarettes/day in the first trimester were at increased risk of miscarriage, with an OR of 1.4 (95% CI, 1.0–2.1). No relationship was evident between the number of cigarettes smoked before conception and the risk of abortion. Likewise, no association emerged between paternal smoking and miscarriage. Moreover, no significant interaction or modification effect was obtained when strata of age and other major characteristics were investigated.

CONCLUSIONS: The risk of abortion associated with cigarette smoking during the first trimester of pregnancy was measurable and noticeable in this population, and accounted for 9% (95% CI, 6–13%) of all cases. The increased risk of spontaneous abortion in women smoking during pregnancy is a further reason to encourage pregnant women to quit.     

Active and passive smoking and risk of breast cancer by age 50 years among German women

Recent studies suggest that both active and passive smokers have an increased risk of breast cancer compared with women who have never been either actively or passively exposed. Data on lifetime active and passive smoking were collected in 1999-2000 from 468 predominantly premenopausal breast cancer patients diagnosed by age 50 years and 1,093 controls who had previously participated in a German case-control study conducted in 1992-1995. Compared with never active/passive smokers, former smokers and current smokers had odds ratios of 1.2 (95% confidence interval (CI): 0.8, 1.7) and 1.5 (95% CI: 1.0, 2.2), respectively, and ever active smokers had an odds ratio of 1.3 (95% CI: 0.9, 1.9). The risk increased with duration of smoking and decreased after cessation of smoking. Among never active smokers, ever passive smoking was associated with an odds ratio of 1.6 (95% CI: 1.1, 2.4). Exposure to environmental tobacco smoke during childhood or before the first pregnancy did not appear to increase breast cancer risk. At greatest risk were women who had a high level of exposure to both passive and active smoking (odds ratio = 1.8, 95% CI: 1.2, 2.7). This study strengthens the hypothesis of a causal relation between active and passive smoke exposures and breast cancer risk.     

Cigarette smoking and the risk of breast cancer

The authors examined the relation between cigarette smoking and breast cancer in the Centers for Disease Control Cancer and Steroid Hormone Study, a multicenter, population-based case-control study. The study compared 4,720 women aged 20-54 years with newly diagnosed breast cancer identified through population-based tumor registries with 4,682 women randomly selected from the same geographic areas. Women who reported ever smoking cigarettes had a risk of breast cancer of 1.2 (95 percent confidence interval 1.1-1.3) compared with never smokers. There was no consistent dose-response pattern with any measure of smoking (pack-years of smoking, average number of cigarettes per day, or total years smoked) and little difference in risk between current and former smokers. There was some variation in risk by age, with slightly higher risk estimates for younger women than for older women. Although current smokers had an earlier natural menopause than did never smokers, the authors found no evidence of a protective effect of cigarette smoking on breast cancer risk. These findings suggest that the risk of breast cancer in women who smoke is the same as, or perhaps slightly higher than, women who have never smoked.     

Breast cancer and cigarette smoking: a hypothesis

In many studies, cigarette smoking has been associated with a small increase in breast cancer risk. The authors evaluated the relation of smoking to breast cancer risk in two case-control studies carried out from 1982 through 1986. In Canada, 607 women with breast cancer and 1,214 controls matched on decade of age and neighborhood were interviewed at home. In the United States, 1,955 cases of breast cancer and 805 controls with other cancers were interviewed in the hospital. In both studies, breast cancer risk was associated weakly with cigarette smoking overall. The odds ratio for women who had smoked 25 or more cigarettes per day as compared with never smokers was 1.2 (95% confidence interval (CI) 0.9-1.6) in the Canadian study and 1.2 (95% Cl 0.9-1.6) in the US study. In both studies, breast cancer risk was more strongly related to commencement of smoking at a young age. Among women who smoked at least 25 cigarettes per day in the most recent year of smoking, the odds ratios for commencement before age 16 years were 1.7 (95% Cl 1.0-2.9) in the Canadian data and 1.8 (95% Cl 1.0-3.4) in the US data, and the odds ratios for commencement at even younger ages were higher. The associations were not explained by duration of smoking, by the time elapsed since commencement, or by factors associated with cigarette smoking such as alcohol consumption or oral contraceptive use. Our findings raise the hypothesis that exposure to cigarette smoke during adolescence may increase a woman's risk of breast cancer. The hypothesis has biologic plausibility: cigarette smoke contains known carcinogens, and the developing breast is especially susceptible to cancer initiation.     

Cigarette smoking and increased risk of mucinous epithelial ovarian cancer

Several studies have reported that cigarette smoking is associated with an increased risk of mucinous ovarian cancer, but other studies have failed to find such a relation. Using data from the Case-Control Surveillance Study, begun in four US cities in 1976, the authors conducted a case-control study (1976-2001) to examine the association between cigarette smoking and the risk of ovarian cancer of different cell types. Among 709 incident cases of epithelial ovarian cancer, 402 were serous, 74 were mucinous, 106 were endometrioid, and 127 were of other cell types. For mucinous ovarian cancer, the odds ratios were 1.5 (95% confidence interval (CI): 0.7, 3.4) among women who smoked less than one pack of cigarettes per day, 1.4 (95% CI: 0.6, 3.5) among women who smoked one pack per day, and 2.9 (95% CI: 1.2, 7.5) among women who smoked more than one pack per day, relative to never smokers. The odds ratios were 2.5 (95% CI: 1.1, 5.4) for ex-smokers and 1.4 (95% CI: 0.7, 2.9) for current smokers. While women with up to 15 pack-years of smoking had an almost 2.5 times' increased risk of mucinous ovarian cancer, such an increased risk was not found among those with more than 15 pack-years of smoking. There was no association between cigarette smoking and epithelial ovarian cancer of other cell types. Despite inconsistencies in the data, these results strengthen the evidence that cigarette smoking may play a role in the development of mucinous ovarian cancer but not ovarian cancer of other cell types.     

Serum bilirubin concentration in a Belgian population: the association with smoking status and type of cigarettes

BACKGROUND: The endogenous antioxidant serum bilirubin may scavenge free radical species from cigarette smoke. Smokers are expected to have lower serum bilirubin levels than never smokers, but this has never been evaluated in a random population sample of women and men. In addition, in vitro studies indicate that filter cigarette smoke might enhance bilirubin oxidation more than non-filter cigarette smoke. METHODS: In this paper, data were analysed from the Belgian Interuniversity Research on Nutrition and Health (BIRNH) study. We investigated the association of smoking and type of cigarettes with serum bilirubin concentrations in men and women using multiple regression models taking into account differences in baseline and smoking characteristics. RESULTS: In men, current smokers had lower crude and adjusted serum bilirubin concentrations compared with never smokers (P = 0.0001). For women, the association between smoking and serum bilirubin concentrations adjusted for age was in the same direction as for men, but did not reach statistical significance. Male former smokers had serum bilirubin concentrations in between those of current smokers and never smokers, while female former smokers had even higher (+ 0.50 micromol/l) serum bilirubin concentrations than never smokers. Male subjects smoking filter cigarettes showed a higher serum bilirubin concentration than those smoking cigarettes without a filter (adjusted difference: 0.49 micromol/l; P = 0.03). The duration of smoking was inversely and significantly related to serum bilirubin concentrations (P = 0.0003). CONCLUSION: Smoking may lower serum bilirubin concentrations in men, especially in those smoking non-filter cigarettes. The duration of smoking is a more important determinant for serum bilirubin concentrations than the number of cigarettes smoked per day, which may indicate the cumulative negative effects of smoking on the endogenous antioxidant system. Results for females pointed in the same direction, but were less clear, possibly due to low numbers of smoking women, who were largely young and smoked mainly filter cigarettes for a shorter period of time.     

Active and passive smoking and the occurrence of natural menopause.

We examined smoking in relation to natural menopause in 543 women who prospectively recorded menstrual data from their 20s. Mean age at natural menopause was 0.8 years younger (95% CL = -1.5, -0.0) in 98 women who smoked at menopause compared with 362 never-smokers (RR 1.3, 95% CI = 1.0-1.7). We did not observe a decrease in age at natural menopause in former smokers, a dose-response among current smokers, or a lower age at menopause with passive smoke exposure at home. These results suggest that the effect of smoking on ovarian senescence is limited to active smoking during the menopausal transition.     

Smoking habits and risk of benign breast disease

The relationship between smoking habits and the risk of benign breast disease (BBD) was analyzed using data from a case-control study conducted between 1981 and 1983 in the greater Milan area, Northern Italy. Cases (n = 288) were women with histologically confirmed BBD (203 dysplasia, 85 benign tumours) referred to the National Cancer Institute of Milan for biopsies. Controls were women (n = 291) seen on selected days for a cytological smear for cervical cancer in outpatient clinics of the same Institute. No consistent association emerged between various indicators of smoking habits (smoking status, number of cigarettes smoked per day, duration of smoking) and the risk of BBD. Compared with never smokers the relative risk (RR) of all BBD combined was 0.7 (95% confidence interval, Cl: 0.4-1.3) in exsmokers, 1.4 (95% Cl: 0.8-2.5) in smokers of less than 10 cigarettes per day, and 1.1 (95% Cl: 0.7-1.7) in smokers of 10 or more cigarettes per day. There was some suggestion that the risk may be below unity post-menopause, but the relative risks for smokers were not statistically different in pre- (RR = 1.2; 95% Cl: 0.8-1.8) and post-menopausal (RR = 0.6; 95% Cl: 0.2-1.7) women. The risk of benign tumours (chiefly fibradenoma) was higher in current smokers, but this finding was not statistically significant (RR = 1.5; 95% Cl: 0.9-2.6) and the highest risks were observed in the strata of lighter smokers and those with shorter duration of smoking. Overall these results fail to support a negative association between smoking habits and benign breast disease.     

Cigarette smoking and breast cancer.

An epidemiological case-control study was conducted in New York State, with 1617 primary breast cancer patients and an equal number of controls, to examine the relationship between cigarette smoking and breast cancer. Results showed no overall association between ever smokers versus never smokers and breast cancer risk (odds ratio [OR] = 1.03, 95% confidence interval [CI]: 0.90-1.19), nor was there any dose response trend observed with increased levels of smoking. In addition, no association was found with risk and age started smoking, age stopped smoking, amount smoked or total years smoked. Controlling for previously identified risk factors for breast cancer in the analysis did not significantly alter these relationships. Previous studies have found a difference in menopausal age among smokers compared to nonsmokers. The mean menopausal age was only slightly lower in smokers than in never smokers for both cases and controls. Breast cancer risk was observed to be close to unity for premenopausal women (OR = 0.97, 95% CI: 0.74-1.34) and postmenopausal women (OR = 1.06, 95% CI: 0.91-1.26). A recent study suggested breast cancer risk was more strongly related to starting smoking at a young age among women who smoked at least 25 or more cigarettes per day in the most recent year of smoking. This hypothesis was not supported by these data.     

Cigarette smoking and the risk of natural menopause

We reviewed published studies on the association of age at natural menopause and cigarette smoking. All demonstrated an earlier median or mean age of menopause among smokers; for current smokers vs noncurrent smokers the difference ranged from 0.8 to 1.7 years. For studies that presented suitable data, we computed prevalence odds ratios of menopause for current smokers vs never-smokers, current smokers vs noncurrent smokers, and former smokers vs never-smokers. The Mantel-Haenzel summary odds ratios and 95% confidence intervals for these contrasts were: 1.9 (1.7-2.2), 1.7 (1.5-1.9), and 1.3 (1.0-1.7). Studies that presented data on amount of cigarettes smoked per day demonstrated "dose-response" trends when analyzed using the Mantel-Haenszel extension. The consistency of results across studies, the persistence of the effect when age and other covariates were considered, and the dose-response relation all support the hypothesis that smoking increases the risk of early menopause.     

Association of active and passive smoking with occupational injury in manual workers: a cross-sectional study of the 2011 Korean working conditions survey

This study was conducted to investigate the relationship of active and passive smoking with occupational injury among manual workers. Data from the 2011 Korean Working Conditions Survey were analyzed for 12,507 manual workers aged ≥15 yr. Overall, 60.4% of men and 5.8% of women were current smokers. The prevalence of injury was higher among never smokers who were exposed to secondhand smoke (SHS) (7.7% in men and 8.1% in women) than current smokers (4.2% in men and 4.1% in women). After controlling for potential confounders, in men, compared to those who never smoked and were not exposed to SHS, people who never smoked and were exposed to SHS (adjusted odds ratio (aOR)=3.7, 2.2–6.4) and current smokers (aOR=2.5, 1.6–3.8) were more likely to experience injury. Among women, the aORs of occupational injury were 8.4 (4.2–16.7) for never smoking women with occasional exposure to SHS and 3.5 (95% CI: 1.4–8.7) for current smokers, in comparison to never smoking women who were never exposed to SHS at work (reference group). The present study suggests that exposure to SHS is a possible risk factor of occupational injury for never smoking men and women.     

Tobacco smoking in relation to pain in a national general population survey

BACKGROUND: We examined whether smoking status including heavy smoking (20 or more cigarettes per day) is related to the number of pain locations and intensity of pain. METHODS: A probability sample of the German national population aged 18 to 79 including 7124 participants (response proportion: 61.4%) was used. All individuals underwent a health examination between 1997 and 1999. Ordinal logistic regression analyses were performed with number of pain locations and pain intensity as dependent variables which had been assessed by questionnaire. RESULTS: Former and current heavy smokers had higher odds for greater numbers of pain locations and for moderate and intense pain than never smokers after adjustment for analgesic medicament use and behavior-related risk factors. Female former heavy smokers had an adjusted odds ratio (OR) of 1.6 (95% confidence interval, CI, 1.2-2.2) and male former heavy smokers had an adjusted OR of 1.4 (CI 1.1-1.8) for higher numbers of pain locations compared to never smoking women and men respectively (female current smokers: OR 1.4, CI 1.0-1.9; male current smokers: OR 1.3, CI 1.1-1.7). CONCLUSION: The findings suggest that former and current heavy smokers are more likely to report more pain locations and more intense pain than never smokers.     

Smoking and health: the association between smoking behaviour, total mortality, and cardiorespiratory disease in west central Scotland.

The relationship of smoking to total mortality and to the prevalence of cardiorespiratory symptoms has been studied in three prospective surveys in west central Scotland in which 18 786 people attended a multiphasic screening examination. The prevalence of respiratory symptoms, and to a lesser extent cardiovascular symptoms, increased with the number of cigarettes smoked, with inhalation, and with a younger age of starting to smoke. A lower prevalence of respiratory symptoms in both sexes was observed in smokers of filter cigarettes than in smokers of plain cigarettes, and in those who smoked cigarettes with lower tar levels, irrespective of whether these were filtered or plain. In general, the relationships found between smoking and mortality were similar to those reported by other workers. Current cigarette smokers had a death rate from all causes which was twice that of those who had never smoked. No difference was found between the mortality rates of smokers of plain and filter cigarettes.     

Exposure to tobacco smoke in utero and the risk of stillbirth and death in the first year of life

The authors examined the association between exposure to tobacco smoke in utero and the risk of stillbirth and infant death in a cohort of 25,102 singleton children of pregnant women scheduled to deliver at Aarhus University Hospital, Aarhus, Denmark, from September 1989 to August 1996. Exposure to tobacco smoke in utero was associated with an increased risk of stillbirth (odds ratio = 2.0, 95% confidence interval: 1.4, 2.9), and infant mortality was almost doubled in children born to women who had smoked during pregnancy compared with children of nonsmokers (odds ratio = 1.8, 95% confidence interval: 1.3, 2.6). Among children of women who stopped smoking during the first trimester, stillbirth and infant mortality was comparable with that in children of women who had been nonsmokers from the beginning of pregnancy. Conclusions were not changed after adjustment in a logistic regression model for the sex of the child; parity; or maternal age, height, weight, marital status, years of education, occupational status, and alcohol and caffeine intake during pregnancy. Approximately 25% of all stillbirths and 20% of all infant deaths in a population with 30% pregnant smokers could be avoided if all pregnant smokers stopped smoking by the sixteenth week of gestation.     

What determines mortality risk in male former cigarette smokers?

OBJECTIVES. The purpose of this study was to examine what factors determine the mortality experience of male ex-cigarette smokers, those who no longer smoke at all and those who changed to pipe or cigar smoking. METHODS. A cohort study was undertaken with 18-year mortality data on 19,018 men. RESULTS. Ex-cigarette smokers had an intermediate mortality risk compared with never and current smokers. Ex-cigarette smokers who switched to pipe smoking had higher mortality than those who no longer smoked at all. The mortality rates for pipe and cigar smokers who were former cigarette smokers were higher than those for pipe or cigar smokers who had never smoked cigarettes. Ex-cigarette smokers who consumed more than 20 cigarettes per day for more than 20 years experienced increased mortality for both coronary heart disease and neoplasms, even after 30 years of cessation. CONCLUSIONS. These results support the notion that an elevated mortality risk may be seen for ex-cigarette smokers, even after they have given up smoking for many years. Ex-cigarette smokers who change to a pipe have a greater mortality risk than those who no longer smoke at all.     

Effects of passive smoking on ischemic heart disease mortality of nonsmokers. A prospective study

The mortality attributable to ischemic heart disease as a result of cigarette smoking is greater of a community of older adults in southern California, the authors tested the hypothesis that nonsmoking women exposed to their husband's cigarette smoke would have an elevated risk of fatal ischemic heart disease. Married women aged 50-79 years who had never smoked cigarettes (n = 695) were classified according to the husband's self-reported smoking status at entry into the study: never, former, or current smoker. After 10 years, nonsmoking wives of current or former cigarette smokers had a higher total (p less than or equal to 0.05) and age-adjusted (p less than or equal to 0.10) death rate from ischemic heart disease than women whose husbands never smoked. After adjustment for differences in risk factors for heart disease, the relative risk for death from ischemic heart disease in nonsmoking women married to current or former cigarette smokers was 14.9 (p less than or equal to 0.10). These data are compatible with the hypothesis that passive cigarette smoking carries an excess risk of fatal ischemic heart disease.     

Parental cigarette smoking and the risk of spontaneous abortion.

Although cigarette smoking is often considered a risk factor for spontaneous abortion, the epidemiologic literature is actually inconsistent. Therefore, the authors examined maternal and paternal smoking and maternal passive smoke exposure using data from a large case-control study of spontaneous abortion (626 cases and 1,300 controls) conducted in Santa Clara County, California, in 1986 and 1987. No excess risk of spontaneous abortion was seen in the 1% of women who smoked an average of more than 20 cigarettes per day in the first trimester. Moderate smokers (11-20 cigarettes per day) had a slightly elevated crude odds ratio of 1.3 (95% confidence interval 0.9-1.9), which was close to unity after adjustment for covariates. Paternal smoking showed a slight crude elevation for moderate and heavy smoking, but no association after adjustment. In contrast, maternal exposure to environmental tobacco smoke for 1 hour or more per day was associated with spontaneous abortion, even after adjustment (odds ratio = 1.5, 95% confidence interval 1.2-1.9). For both maternal direct and environmental exposure, the association appeared to be stronger in second-trimester abortions. Several studies have found stronger associations of smoking with late versus early abortions, perhaps reflecting smoking-associated placental insufficiency and fetal hypoxia.     

Smoking habits and type 2 diabetes mellitus in women

The purpose of this case–control study was to evaluate the relationship between smoking and type 2 diabetes mellitus (T2DM) in adult females. A total of 168 women in Kaunas, Lithuania with newly diagnosed T2DM during the year 2001 and 336 controls who were women without diabetes were recruited. Participants were asked about their duration of smoking, the number of cigarettes smoked per day, pack-years, and smoking cessation. Odds ratios (OR), 95 percent confidence intervals (CI) for T2DM were calculated using conditional logistic regression. After adjustment for possible confounders, women with T2DM had a nearly threefold higher odds for smoking 10 or more cigarettes per day compared with controls and using never smokers as the referent category (OR = 2.8; 95 percent CI 1.0–7.7). Women with T2DM had over fourfold odds for having smoked for 40 years or more compared to controls (OR = 4.6; 95 percent CI 1.1–18.6). Compared to controls, women with T2DM had over a sixfold higher odds for stopping smoking for 19 or fewer years with never smokers as the referent category (OR = 6.4; 95 percent CI 1.5–27.3). The findings of our study suggest a possible relationship between smoking and T2DM in women. Also, despite smoking cessation, the association with T2DM remained for a long time.     

Tobacco smoking and acute myocardial infarction in young adults: a population-based case-control study

OBJECTIVE: To evaluate the effect of tobacco smoking on the risk of non-fatal acute myocardial infarction in young adults (< or = 45 years), and whether there is modification of this effect by sex. METHODS: We conducted a population-based case-control study with 329 incident acute myocardial infarction cases (42 women; 287 men), consecutively admitted to the Cardiology department of hospitals in Porto, Portugal, and 778 controls (486 women; 292 men), selected within the non-institutionalized Porto population, during 2001-2003. Odds ratios and 95% confidence intervals (OR, 95%CI) were calculated using unconditional logistic regression. RESULTS: The prevalence of current smoking was 80.8% in male cases and 53.8% in male controls (OR=3.63, 95%CI: 2.50, 5.27) and 59.5% of female cases were smokers compared to 35.8% of controls (OR=2.64, 95%CI: 1.39, 5.02). No interaction was found between current smoking and sex on myocardial infarction risk (p=0.401). A dose-effect response was present, the odds favoring myocardial infarction reaching an eight-fold increase for those that smoked > 25 cigarettes/day compared to never smokers. The risk estimate for former smokers was similar to never smokers. CONCLUSIONS: Tobacco smoking is an important independent risk factor for acute myocardial infarction in young adults, with similar strength of association for both sexes.     

The effect of cigarette smoking on the risk of preeclampsia and gestational hypertension

This case-control study assessed the relation of cigarette smoking during pregnancy to the risk of preeclampsia and gestational hypertension. All subjects were primiparous women without a history of high blood pressure who gave birth in Quebec City or Montreal, Canada, hospitals between 1984 and 1986. Cases (172 women with preeclampsia and 251 with gestational hypertension) and 505 controls were interviewed at the hospital after delivery. Adjusted relative risks were estimated by polychotomous logistic regression. Compared with women who had never smoked, women who were smokers at the onset of pregnancy had a reduced risk of preeclampsia (relative risk = 0.51, 95% confidence interval 0.34-0.77). Relative risks of preeclampsia decreased with increases in the number of cigarettes smoked daily at the onset of pregnancy: Relative risks among smokers of less than 11, 11-20, and more than 20 cigarettes per day were 0.79, 0.56, and 0.38, respectively (test for trend: p = 0.0002). The protective effect of smoking on preeclampsia was stronger for women who continued to smoke after 20 weeks of pregnancy. While smoking tended to reduce the risk of gestational hypertension, this effect was less evident than that for preeclampsia. Relative risks varied little with severity of disease as based on gestational age at the onset of hypertension, maximal blood pressure and, for preeclampsia, amount of proteinuria. The reduction in mean birth weight attributable to smoking during pregnancy was similar among cases and controls. Nicotine inhibition of thromboxane A2 production might explain the decreased risk of pregnancy-induced hypertension among smokers. Despite these findings, the harmful consequences of smoking on pregnancy outcome outweigh its protective effect against pregnancy-induced hypertension.