Risk factors for abruptio placentae

The authors studied the relation of sociodemographic, medical, and life-style factors and abruptio placentae in a large cross-sectional data base. The 143 cases of abruption identified in the Delivery Interview Program, conducted in Boston from 1977 to 1980, were compared with 1,257 randomly selected controls. The authors used multiple logistic regression techniques to derive maximum likelihood estimates of the adjusted odds ratios and 95% confidence intervals as measures of the association between exposure factors and abruption. A history of chronic hypertension was associated with a threefold increase in risk (odds ratio (OR) = 3.1, 95% confidence interval (Cl) 1.1-8.4), but pregnancy-induced hypertension was not associated with abruption. Excess risk was associated with advanced maternal age (OR = 2.3, 95% Cl 1.3-3.9), low prepregnancy body mass index (OR = 2.3, 95% Cl 1.3-4.1), a history of prior stillbirth (OR = 3.5, 95% Cl 1.8-7.0), and at least weekly use of marijuana during pregnancy (OR = 2.8, 95% Cl 1.2-6.6). Overall, the association with cigarette smoking during pregnancy was of only borderline significance (OR = 1.5, 95% Cl 1.0-2.2), although there appeared to be a dose-response relation between the number of cigarettes smoked and risk of abruption.     

Influence of maternal smoking on placental abruption in successive pregnancies: a population-based prospective cohort study in Sweden

The authors examined associations between cumulative smoking during a woman's first and second pregnancies and risk of placental abruption in the second pregnancy. They performed a population-based prospective cohort study of 526,690 women who delivered their first two consecutive singletons in Sweden in 1983-2001. Using logistic regression models, the authors found that, among women without placental abruption in the first pregnancy, smoking was associated with increased risk of abruption in the second pregnancy; however, this effect was confined to exposure occurring during the second pregnancy (adjusted odds ratio (OR)=1.8, 95% confidence interval (CI): 1.4, 2.3) but not the first (adjusted OR=1.1, 95% CI: 0.9, 1.3). Among women with a prior abruption, the risk of repeating abruption was increased irrespective of smoking habits. When women smoked during both pregnancies, there was an almost 11-fold increase in risk (adjusted OR=10.9, 95% CI: 7.3, 16.3). These findings suggest that women who quit smoking before pregnancy may benefit from reduced risk of abruption. The observation that the recurrence of abruption is substantially increased regardless of changes in smoking habits suggests that factors other than smoking may influence the recurrence of placental abruption.     

The relationships of gender, cigarette smoking, and hypertension with the risk of aneurysmal subarachnoid hemorrhage: a case-control study in Nagoya, Japan

PURPOSE: To examine the relationship of gender, cigarette smoking, and a history of hypertension to the risk of aneurysmal subarachnoid hemorrhage (SAH), using a case-control study. METHODS: Case subjects consisted of a consecutive series of 201 patients with spontaneous SAH with aneurysm(s) confirmed by angiography and/or CT scan. One hospital and one community control subject was matched to each case by gender and age (+/- 2 years). Multiple conditional logistic regression was used to calculate the odds ratio (OR) and 95% confidence interval (CI) adjusted for potential confounders. RESULTS: Current smoking and a history of hypertension were each significantly associated with an increased risk of subarachnoid hemorrhage for men and women combined. There was also a non-significant trend towards synergism between these two factors with respect to an increased risk of subarachnoid hemorrhage for each gender separately and both combined. A significantly increased risk was observed for a history of hypertension (adjusted OR, 3.5; 95% CI, 1.2-14.7) among men, for current smoking alone (adjusted OR, 2.9; 95% CI, 1.1-7.7), and a history of hypertension alone (adjusted OR, 2.6; 95% CI, 1.4-5.1) among women. CONCLUSIONS: Trends towards gender differences and synergism emerged in the relationship of cigarette smoking and a history of hypertension of the risk of SAH provides useful information for targeting individuals/populations in programs for the primary prevention of SAH by gender.     

Cigarette smoking and risk of adult leukemia

A case-control study investigated the relation between cigarette smoking and histologic subtypes of adult leukemia in Missouri in 1984-1990. Among males, elevated risks associated with ever smoking were observed for acute nonlymphocytic leukemia (odds ratio (OR) = 1.5; 95% confidence interval (CI) 1.1-2.0) and acute myelocytic leukemia (OR = 1.5; 95% CI 1.1-2.1). Females also showed an increased risk of acute nonlymphocytic leukemia associated with ever smoking (OR = 1.4; 95% CI 1.0-1.9), with an increasing trend in risk by level of smoking (p less than 0.01). Attributable risk estimates of the proportion of acute nonlymphocytic leukemia caused by smoking were 33 percent in males and 29 percent in females. Elevations in risk were not apparent for chronic forms of leukemia. The findings support the hypothesis that some types of leukemia may be etiologically related to cigarette smoking.     

Risk factors in term children for visual impairment without a known prenatal or postnatal cause

Risk factors were studied for visual impairment in children without known pre- or postnatal cause, for a decrease of visual acuity. Children born at term 1979-98 and with a visual impairment were identified from the Swedish Register of Visually Impaired Children and data were linked with the Swedish Medical Birth Registry. Maternal characteristics such as maternal age, parity, maternal smoking habits in early pregnancy, maternal education, nationality, and subfertility were studied as well as maternal diagnoses such as pre-eclampsia, prolonged second stage of labour, abruptio placentae, and placenta praevia. Mode of delivery was analysed as well as birthweight, and birthweight in relation to gestational age. Abruptio placentae turned out to be the strongest risk factor (OR = 8.24 [95% CI 5.01, 13.51]). Smoking did not give a statistically significant increased risk. There is an increased risk with breech delivery (OR = 2.01 [95% CI 1.28, 3.17]). Pre-eclampsia was associated with an increased risk (OR = 2.22 [95% CI 1.46, 3.38]). There is also an increase in risk at low birthweight and small-for-gestational-age as well as birthweight > 4 kg and large-for-gestational-age. In this study we found that risk factors particularly worth noticing in term children with a presumed perinatal cause of visual impairment are abruptio placentae, pre-eclampsia, excessively low as well as excessively high birthweight, and breech delivery, a fact worth noticing in current discussion on risks, advantages or excessive exploitation of caesarean section.     

天津市部分女性高血压危险因素的探讨

对天津市河东区居民中301例女性原发性高血压病人进行了1:1配对病例对照研究。经条件Logistic回归模型分析,与高血压有关的危险因素是:体重(OR=1.17,95% CI:1.12~1.23),高血压家族史(OR=2.18,95% CI:1.49~3.21),人均收入(OR=0.73,95% CI:0.56~0.94),心率(OR=2.30,95% CI:1.41~3.76),初潮年龄(OR=0.90,95% CI:0.82~0.99)。经体重的混杂调整后,除初潮年龄外其他因素的OR值仍有统计学显著性意义。未发现绝经年龄、产次、初产年龄、服避孕药史和吸烟与高血压有关。     

N-acetyltransferase 2 polymorphisms, tobacco smoking, and breast cancer risk in the breast and prostate cancer cohort consortium

Common polymorphisms in the N-acetyltransferase 2 gene (NAT2) modify the association between cigarette smoking and bladder cancer and have been hypothesized to determine whether active cigarette smoking increases breast cancer risk. The authors sought to replicate the latter hypothesis in a prospective analysis of 6,900 breast cancer cases and 9,903 matched controls drawn from 6 cohorts (1989-2006) in the National Cancer Institute's Breast and Prostate Cancer Cohort Consortium. Standardized methods were used to genotype the 3 most common polymorphisms that define NAT2 acetylation phenotype (rs1799930, rs1799931, and rs1801280). In unconditional logistic regression analyses, breast cancer risk was higher in women with more than 20 pack-years of active cigarette smoking than in never smokers (odds ratio (OR) = 1.28, 95% confidence interval (CI): 1.17, 1.39), after controlling for established risk factors other than alcohol consumption and physical inactivity. However, associations were similar for the slow (OR = 1.25, 95% CI: 1.11, 1.39) and rapid/intermediate (OR = 1.24, 95% CI: 1.08, 1.42) acetylation phenotypes, with no evidence of interaction (P = 0.87). These results provide some support for the hypothesis that long-term cigarette smoking may be causally associated with breast cancer risk but underscore the need for caution when interpreting sparse data on gene-environment interactions.     

Passive smoking, cytochrome P450 gene polymorphisms and dysmenorrhea

PURPOSE: This study investigated whether the association between passive smoking exposure and dysmenorrhea is modified by two susceptibility genes, CYP1A1MspI and CYP1A1HincII. METHODS: This report includes 1,645 (1,124 no dysmenorrhea, 521 dysmenorrhea) non-smoking and non-drinking newly wedding female workers at Anqing, China between June 1997 and June 2000. Multiple logistic regression models were used to estimate the associations of passive smoking exposure and genetic susceptibility with dysmenorrhea, adjusting for maternal age, BMI, age of menarche, education, vibration exposure, shift work, noise exposure, pregnancy history, perceived stress and physical laboring stress. RESULTS: In the passive smoking group, women who have C/C6235 genotype (OR = 1.8, 95% CI = 1.0-3.3) in CYP1A1MspI and Ile/Ile462 genotype (OR = 2.9, 95% CI = 1.1-7.7) in CYP1A1HincII was associated with an increased risk of dysmenorrhea. When stratified by women genotype, the adjusted OR of dysmenorrheal was 1.6 (95% CI = 1.2-2.1) for passive smoking group with Ile/Ile462 genotype, and 1.5 (95% CI = 1.0-2.1) with C/C6235 genotype, compared to non-passive smoking group, respectively. The data further showed that there was a significant combined effect between passive smoking and the CYP1A1 Msp1C/C6235 (OR = 1.5, 95% CI = 1.0-2.1), and HincII Ile/Ile462 (OR = 1.6, 95% CI = 1.2-2.1), respectively. CONCLUSION: CYP1A1 MspI and HincII genotypes modified the association between passive smoking and dysmenorrhea.     

Cigarette smoking and risk of Hodgkin's disease: a population-based case-control study

Previous reports offer limited support for an association between cigarette smoking and Hodgkin's disease. The authors investigated dose-response effects for smoking in relation to the risk of Hodgkin's disease using data from the Selected Cancers Study. Cases (n = 343) were men aged 32-60 years identified from eight US population-based cancer registries in 1984-1988. Controls (n = 1,910) were men recruited by random digit telephone dialing and frequency matched to cases by age and registry. Conditional logistic regression was used to calculate odds ratios and 95% confidence intervals adjusted for age, registry, race/ethnicity, Jewish upbringing, education, and childhood domicile. Compared with never smokers, current smokers had a significantly increased risk of Hodgkin's disease (odds ratio (OR) = 1.8, 95% confidence interval (CI): 1.3, 2.9). Risks increased linearly (p < 0.001) with increasing packs per day (OR(>or=2) = 2.5, 95% CI: 1.6, 4.0), years (OR(>or=30) = 2.4, 95% CI: 1.5, 3.9), and pack-years (OR(>40) = 2.7, 95% CI: 1.8, 4.3) of smoking. These associations were significant for the nodular sclerosis and mixed cellularity subtypes but were much stronger for mixed cellularity. Stratified analyses by age (42 years) and subtype suggested that the effects of smoking are more closely related to histology than age. In contrast to findings from previous studies, these data suggest that smoking is an important preventable risk factor for Hodgkin's disease.     

Nasopharyngeal carcinoma in Malaysian Chinese: occupational exposures to particles, formaldehyde and heat

BACKGROUND: During 1990-1992, 282 Chinese residents of Selangor and the Federal Territory, Malaysia with histologically confirmed nasopharyngeal carcinoma (NPC) were interviewed about occupational history, diet, alcohol consumption, and tobacco use, as were an equal number of Malaysian Chinese population controls, pair-matched to cases by age and sex. METHODS: Exposures to 20 kinds of workplace substances, solar and industrial heat, and cigarette smoke, were analysed by univariate and multivariate methods. RESULTS: Nasopharyngeal carcinoma was associated with occupational exposures to construction, metal and wood dusts; motor fuel and oil; paints and varnishes; certain other chemicals; industrial heat; solar heat from outdoor occupations; certain smokes; cigarette smoking; and childhood exposure to parental smoking. After adjustment for risk from diet and cigarette smoke, only wood dust (OR = 2.36; 95% CI : 1.33- 4.19), and industrial heat (OR = 2.21; 95% CI : 1.12-4.33) remained clearly associated. Wood dust remained statistically significant after further adjustment for social class. No significant crude or adjusted association was found between NPC and formaldehyde (adjusted OR = 0.71; 95% CI : 0.34-1.43). CONCLUSIONS: This study supports previous findings that some occupational inhalants are risk factors for NPC. The statistical effect of wood dust remained substantial after adjustment for diet, cigarette smoke, and social class. Intense industrial heat emerged as a previously unreported risk factor, statistically significant even after adjustment for diet and cigarette smoke. No association was found between NPC and formaldehyde.     

Cocaine use during pregnancy: perinatal outcomes

The relation between maternal cocaine use and perinatal outcomes was investigated among 17,466 non-Asian singleton deliveries in 1988 from the University of Illinois Perinatal Network data base in the metropolitan Chicago area. Elevated adjusted relative risks (RR) of low birth weight (RR = 2.8, 95% confidence interval (CI) 2.2-3.7), prematurity (RR = 2.4, 95% CI 1.9-3.1), abruptio placentae (RR = 4.5, 95% CI 2.4-8.5), and perinatal death (RR = 2.1, 95% CI 1.1-4.0) were observed for "any" cocaine users (n = 408) compared with women who did not use cocaine or any other drugs or alcohol (n = 17,058). There was an increased (although unstable) risk of intrapartum placenta previa not previously reported (RR = 2.3, 95% CI 1.0-5.1). The relative risk of small-for-gestational-age births for cocaine users who did not smoke (RR = 3.4, 95% CI 1.8-6.5) was greater than that for cocaine users who did (RR = 2.1, 95% CI 1.1-4.1). Irrespective of smoking status, cocaine use during pregnancy increased the risk of small-for-gestational-age births.     

Maternal cigarette smoking and the risk of pregnancy-induced hypertension and eclampsia

BACKGROUND: Although previous studies have found that maternal smoking decreases the risk of pregnancy-induced hypertension (PIH), the difference of this effect between primiparous and multiparous women has not been well studied and the results of the exposure-response relationships between maternal smoking and PIH are inconsistent. No previous study has specifically examined the relationship between maternal smoking and eclampsia. METHODS: We analysed data from a population-based retrospective cohort study of 3 153 944 singleton pregnancies in the US. The data were derived from the national linked birth/infant mortality database for 1998. Multiple logistic regressions were used to describe the relationship between cigarette smoking and PIH and eclampsia. RESULTS: The adjusted odds ratios (ORs) [95% confidence intervals (95% CIs)] for PIH were 0.80 (0.77-0.83) for primiparous women and 0.81 (0.78-0.83) for multiparous women among smokers compared with non-smokers. The corresponding adjusted ORs (95% CIs) for eclampsia were 0.74 (0.66-0.82) and 0.75 (0.68-0.83), respectively. For PIH, the adjusted OR (95% CI) for smokers vs non-smokers were 0.82 (0.79-0.86), 0.81 (0.78-0.83), 0.80 (0.77-0.83), and 0.88 (0.79-0.98), respectively, for 1-5, 6-10, 11-20, and >20 cigarettes per day (test for trend: P = 0.86). The corresponding figures for eclampsia were 0.85 (0.75-0.95), 0.74 (0.66-0.82), 0.68 (0.58-0.78), and 0.73 (0.49-1.04), respectively (test for trend: P = 0.02). CONCLUSION: Maternal cigarette smoking decreases the risk of PIH and eclampsia, with a significant inverse exposure-response relationship apparent for eclampsia.     

CYP1A1 gene polymorphisms in modifying the association between passive smoking and primary dysmenorrhea

PURPOSE: This study investigated whether the association between passive smoking exposure and primary dysmenorrhea is modified by two susceptibility genes, cytochrome P450 1A1 (CYP1A1)MspI and CYP1A1HincII. METHODS: We recruited 1645 female textile workers from 1997 to 2000 in Anqing, China, collecting information about passive smoking and status of primary dysmenorrhea and taking blood samples. We analyzed the association of CYP1A1 gene polymorphisms and passive smoking exposure with primary dysmenorrhea using multiple logistic regression. RESULTS: In the passive smoking group, women who had the C/C6235 genotype (odds ratio [OR] = 1.8; 95% confidence intervals [CI] = 1.0-3.3) in CYP1A1MspI and Ile/Ile462 genotype (OR = 2.9; 95% CI = 1.1-7.7) in CYP1A1HincII had increased risk of dysmenorrhea. When stratified by genotype, the adjusted OR of dysmenorrhea was 1.6 (95% CI = 1.2-2.1) for the passive smoking group with the Ile/Ile462 genotype and 1.5 (95% CI = 1.0-2.1) with the C/C6235 genotype, compared with the nonpassive smoking group. The data further showed that there was a significant combined effect between passive smoking and the CYP1A1MspI C/C6235 and HincII Ile/Ile462 genotypes (OR = 2.4; 95% CI = 1.2-4.9). CONCLUSIONS: CYP1A1MspI and HincII genotypes modified the association between passive smoking and primary dysmenorrhea.     

Reevaluation of the confounding effect of cigarette smoking on the relationship between alcohol use and lung cancer risk, with larynx cancer used as a positive control

BACKGROUND: The effect of smoking on lung cancer risk has been well documented, while the effect of alcohol remains controversial. We examined the hypothesis that the apparent association between alcohol intake and lung cancer risk is fully due to the confounding effect of cigarette smoke. METHODS: Our sample of hospitalized patients included 2,953 male and 1,622 female lung cancer cases; 521 male and 159 female larynx cancers cases; and 8,169 male and 4,154 female controls, admitted to participating hospitals between 1981 and 1994. All controls had been diagnosed with non-smoking-related diseases. Larynx cancer was used as a positive control for lung cancer. Relative risks were estimated through odds ratios, adjusted through multiple logistic regression. RESULTS: Although the odds ratios for alcohol had been significantly elevated prior to adjustment for smoking (OR = 2.4, 95% CI = 2.0-2.8), alcohol had no effect on lung cancer following this adjustment (OR = 1.2, 95% CI = 1.0-1.4). By contrast, the effect of alcohol on larynx cancer remained high even after adjustment for smoking (OR = 5.6, 95% CI = 3.7-8.6). CONCLUSION: The often-reported association between alcohol and lung cancer risk can be fully explained by the confounding effect of cigarette use.     

吸烟对不同收入人群慢性病患病的影响

目的探讨吸烟对不同经济状况人群的健康影响。方法采用多阶段分层整群随机抽样的方法，在全国共抽取95个县、950个村(居委会)，每个样本村(居委会)随机抽取60户家庭，全国共抽取55200户家庭中15～65岁男性5．93万人。结果研究发现在控制年龄、经济状况、文化程度、就业状况、工作岗位的情况下，不论农村、城镇，与从不吸烟的人相比，有吸烟史的人群慢性病患病率均高(农村OR=1．185，95％CI：1．121～1．253；城镇OR=1．083，95％CI：1．010～1．161)；吸烟对农村男性患慢性病的影响(戒烟OR=2．764，95％CI：2．471～3．092)要大于城镇的相应人群(戒烟OR=2．112，95％CI：1．844～2．419)；另外发现吸烟对低收入人口患慢性病的影响(城镇OR=2．076，95％CI：1．551～2．780；农村OR=2．903，95％CI：2．248～3．749)大于对高收入人口的影响(城镇OR=1．785，95％CI：1．285～2．479；农村OR=2．466，95％CI：1．941～3．134)。结论吸烟对收入低下的人群健康损害更大，应该引起重视。     

Placental abruption and perinatal death

Studies of risk factors for abruptio placentae (AP) are partly conflicting and studies of risk factors for perinatal death in these pregnancies are scarce. Using the population-based Swedish Birth Registry from 1987 to 1993, we were able to study these risks in 795,459 singleton pregnancies. Logistic regression analysis was used to estimate odds ratios (OR) for risk of AP and risk of perinatal death in pregnancies with and without AP. Risk factors for AP were: age, primiparity, high parity, not cohabiting with infant's father, low education, smoking, infertility, pregestational diabetes, essential hypertension, pregnancy-induced hypertensive diseases, preterm premature rupture of membranes, preterm birth and small-for-gestational-age (SGA) births. Risk factors for perinatal death in pregnancies with placental abruption were smoking (1--9 and > or =10 cigarettes/day; OR 1.4 and 1.7 respectively), severe pre-eclampsia (OR 2.0) and SGA (OR 1.9), whereas in pregnancies without abruption, risks were also increased in maternal age > or =35 years, primiparity, infertility, essential hypertension and pregestational diabetes. These findings support the theory that, in cases of AP, a general impairment of the placenta and/or a defect placentation may be fatal.     

Relationship between cigarette smoking and oral health status]

The purpose of the study was to examine the relationship between the smoking habit and oral health status, while adjusting for age and some aspects of dental health behavior. The data used were based on a cross-sectional study on dental checkup in the worksite, which included a self-reported questionnaire and oral examination by a dentist. The oral health status variables were CPITN scores, missing teeth/filled teeth/decayed teeth, and self-reported gum bleeding. In addition, the subjects reported in a questionnaire concerning their smoking habit and dental health behavior. Of a total of 7,713 of workers, 5,232 (67.8%) participated in the dental checkup of the worksite. From the population, only the data for 3,303 men were analyzed. We used multiple logistic regression to calculate the odds ratio (OR) for each oral health status according to the smoking habit. Current smokers, compared to subjects who had never smoked, had a higher risk of periodontal disease (OR = 2.3; 95% CI: 1.9-2.7), missing teeth (OR = 1.6; 95% CI: 1.3-1.9) and decayed teeth (OR = 1.5; 95% CI: 1.3-1.8), but they had a reduced risk of gum bleeding (OR = 0.7; 95% CI: 0.6-0.8). Dose response relationships between smoking and these variables were also observed. The results indicated that cigarette smoking was associated with oral health status independent of some aspects of dental health behavior.     

Fetal growth, maternal prenatal smoking, and risk of invasive meningococcal disease: a nationwide case-control study

BACKGROUND: The prenatal period may be important for susceptibility to infections. We evaluated whether low birthweight, prematurity, and prenatal maternal smoking were associated with increased risk of invasive meningococcal disease. METHODS: We linked the Danish nationwide National Registry of Patients, the Birth Registry, and social registries to obtain data on fetal growth and social factors on 1921 cases of meningococcal disease hospitalized between 1 January, 1980 and 31 December, 1999 (median age 31 months, interquartiles 13-65 months) and 37 451 population controls. The impact of maternal smoking was examined in a subsample of 462 cases and 9240 controls born after 1990, when data on smoking became available in the Birth Registry. RESULTS: The adjusted odds ratios (OR) of meningococcal disease associated with low birthweight (<2500 g) varied between 1.6 (95% CI: 1.1, 2.3) in infants <12 months to 1.5 (95% CI: 1.0, 2.3) in children >60 months of age at hospitalization for meningococcal disease. Premature children had an increased risk of meningococcal disease during the first year of life only (adjusted OR = 1.3, 95% CI: 1.1, 1.9). The effect of low birthweight was very similar among mature and premature children. The adjusted OR for maternal smoking was 1.8 (95% CI: 1.4, 2.2). CONCLUSIONS: Low birthweight is associated with an increased risk of meningococcal disease throughout childhood, while an effect of prematurity persists only for 12 months. Maternal prenatal smoking was associated with the risk of meningococcal disease.     

Population-based case-control study of amyotrophic lateral sclerosis in western Washington State. I. Cigarette smoking and alcohol consumption

The associations of cigarette smoking and alcohol consumption with the risk of amyotrophic lateral sclerosis (ALS) were investigated in a population-based case-control study conducted in three counties of western Washington State from 1990 to 1994. Incident ALS cases (n = 161) were identified and were matched to population controls (n = 321) identified through random digit dialing and Medicare enrollment files. Conditional logistic regression analysis was used to compute odds ratios adjusted for age, gender, respondent type, and education. The authors found that alcohol consumption was not associated with the risk of ALS. Ever having smoked cigarettes was associated with a twofold increase in risk (alcohol-adjusted odds ratio (OR) = 2.0, 95% confidence interval (CI): 1.3, 3.2). A greater than threefold increased risk was observed for current smokers (alcohol-adjusted OR = 3.5, 95% CI: 1.9, 6.4), with only a modestly increased risk for former smokers (alcohol-adjusted OR = 1.5, 95% CI: 0.9, 2.4). Significant trends in the risk of ALS were observed with duration of smoking (p for trend = 0.001) and number of cigarette pack-years (p for trend = 0.001). The finding that cigarette smoking is a risk factor for ALS is consistent with current etiologic theories that implicate environmental chemicals and oxidative stress in the pathogenesis of ALS.     

Maternal risk factors and major associated defects in infants with Down syndrome

More than 50% of infants with Down syndrome have associated defects that cause considerable morbidity and mortality. We evaluated the hypothesis that the trisomic genome interacts with environmental factors to increase the risk for specific associated defects. We evaluated risk factors present during early pregnancy in a multiracial population of 687 infants with Down syndrome. Mother's cigarette smoking was associated with the grouped cardiac defects [odds ratio (OR)=2.0; 95% confidence interval (CI) = 1.2-3.2]. When adjusted for other cardiac defects and maternal race, the following specific defects were associated with smoking: atrioventricular canal (OR = 2.3; 95% CI = 1.2-4.5), tetralogy of Fallot (OR = 4.6; 95% CI = 1.2-17.0), and atrial septal defects without ventricular septal defect (OR = 2.2; 95% CI = 1.1-4.3). Hirschsprung disease was associated with mother's daily consumption of more than three cups of coffee (OR = 6.02; 95% CI = 1.2-29.7) and with mother's fever (OR = 3.4; 95% CI = 0.7-16.4), but the number of cases was small. Use of alcohol was not associated with any defect. Mother's race, age, parity, income, or education did not confound the associations. Results suggest that environmental factors can modify the occurrence of associated anomalies in the embryo with Down syndrome.