Maternal smoking and congenital heart defects

The Swedish Child Cardiology Registry (CCR) and the Swedish Medical Birth Registry (MBR) were used to investigate a possible association between maternal smoking during pregnancy and congenital heart defects. Among 1,413,811 infants born in 1983–1996 with known smoking exposure in early pregnancy, 3384 infants with congenital heart defects were selected (458 term infants with persistent ductus arteriosus (PDA) identified from MBR or CCR, and 2926 infants with other heart defects, identified from CCR). After controlling for year of birth, maternal age, parity, and educational level, a weak, statistically significant association between all heart defects and maternal smoking was found (odds ratio (OR): 1.09; 95% confidence interval (CI): 1.01–1.19). When infants with isolated PDA were removed from the case group the significance disappeared (OR: 1.07; 95% CI: 0.98–1.17). For truncus abnormalities (OR: 1.23; 95% CI: 1.02–1.49), atrial septal defects (OR: 1.63; 95% CI: 1.04–2.57), and PDA (OR: 1.30; 95% CI: 1.05–1.62), a rather strong effect of maternal smoking was indicated. The increased OR for PDA remained when gestational duration and intrauterine growth was also controlled for. Further research based on independent data sets is needed to conclude whether the risk estimates for maternal smoking are true and truly differ between the groups. The classification system used (with 24 classes) is described in enough detail to permit a repetition of the study.     

Parental occupational exposure to pesticides and childhood germ-cell tumors

In a recently completed US case-control study (Children's Oncology Group, 1993-2001) with 253 cases and 394 controls, the authors investigated the association between parental occupational exposure to pesticides and risk of childhood germ-cell tumors. Information on occupational pesticide exposure was collected using job-specific module questionnaires and assessed by an experienced industrial hygienist. Odds ratios for childhood germ-cell tumors associated with maternal exposures before pregnancy, during pregnancy, and after the birth of the index child were 1.0 (95% confidence interval (CI): 0.8, 1.4), 1.1 (95% CI: 0.7, 1.6), and 1.3 (95% CI: 0.9, 1.8), respectively. Paternal exposures before pregnancy, during pregnancy, and after the birth of the index child were not related to germ-cell tumors (odds ratios (ORs) were 0.9 (95% CI: 0.7, 1.2), 0.8 (95% CI: 0.5, 1.2), and 0.8 (95% CI: 0.5, 1.3), respectively). When both parents had ever been occupationally exposed to pesticides before the index pregnancy, the odds ratio was 0.8 (95% CI: 0.4, 1.3). Subgroup analyses showed a positive association between maternal exposure to herbicides during the postnatal period and risk of germ-cell tumors in girls (OR = 2.3, 95% CI: 1.0, 5.2) and an inverse association between paternal exposure to pesticides during the index pregnancy and germ-cell tumors in boys (OR = 0.2, 95% CI: 0.1, 1.0). This study did not provide strong evidence supporting a relation between parental pesticide exposure in the workplace and risk of germ-cell tumors among offspring.     

Parental occupational exposures to chemicals and incidence of neuroblastoma in offspring.

To evaluate the effects of parental occupational chemical exposures on incidence of neuroblastoma in offspring, the authors conducted a multicenter case-control study, using detailed exposure information that allowed examination of specific chemicals. Cases were 538 children aged 19 years who were newly diagnosed with confirmed neuroblastoma in 1992-1994 and were registered at any of 139 participating hospitals in the United States and Canada. One age-matched control for each of 504 cases was selected through random digit dialing. Self-reported exposures were reviewed by an industrial hygienist, and improbable exposures were reclassified. Effect estimates were calculated using unconditional logistic regression, adjusting for child's age and maternal demographic factors. Maternal exposures to most chemicals were not associated with neuroblastoma. Paternal exposures to hydrocarbons such as diesel fuel (odds ratio (OR) = 1.5; 95% confidence interval (CI): 0.8, 2.6), lacquer thinner (OR = 3.5; 95% CI: 1.6, 7.8), and turpentine (OR = 10.4; 95% CI: 2.4, 44.8) were associated with an increased incidence of neuroblastoma, as were exposures to wood dust (OR = 1.5; 95% CI: 0.8, 2.8) and solders (OR = 2.6; 95% CI: 0.9, 7.1). The detailed exposure information available in this study has provided additional clues about the role of parental occupation as a risk factor for neuroblastoma.     

尿道下裂危险因素的病例对照研究

目的 探讨尿道下裂病因。方法 采用以医院为基础的1:2配比的病例对照研究方法,以统一的调查表及调查方式对107倒尿道下裂及214例对照进行面对面问卷调查,应用SAS 6.12软件对所有调查因素进行单因素及多因素logistic回归分析。结果 胎儿尿道下裂的发生与母亲孕前自然流产史(OR=3.87,95％CI:1.60～9.39)、孕期发生先兆流产(OR=3.57,95％CI:1.31～9.64)、孕早期感冒伴发热(OR=7.63,95％CI:2.50～23.24)、孕中期用抗感染和/或解热止痛药(OR=16.46,95％CI;3.46～78.21)、父亲职业性接触农药(OR=3.70,95％CI:1.49～9.16)及胎儿低出生体重(OR=12.62,95％CI:2.97～53.67)呈正相关,与母亲孕早期增加蛋白质类营养(OR=0.33,95％CI:O.15～0.74)呈负相关。结论 母亲孕前自然流产史、孕期发生先兆流产、孕早期感冒伴发热、孕中期用抗感染和/或解热止痛药、父亲职业性接触农药、胎儿低出生体重等可能增加胎儿发生尿道下裂的危险,而母亲孕早期增加蛋白质类营养可能降低胎儿发生尿道下裂的危险。     

Maternal prepregnancy weight and congenital heart defects in offspring.

To determine the relation between having an infant with a major heart defect and a mother's prepregnancy weight, we compared 1,049 Atlanta-area women who gave birth to liveborn or stillborn infants, each with a major heart defect, with 3,029 Atlanta-area women who gave birth to infants without birth defects. The infants of control women were randomly selected from birth certificates and were frequency-matched to the case group by race, birth hospital, and birth period from 1968 through 1980. After excluding diabetic mothers and adjusting for potential confounders, compared with average-weight women (body mass index 19.9--22.7), we found that underweight women (body mass index <16.5) were less likely to have a child with a major isolated heart defect [odds ratio (OR) = 0.64; 95% confidence interval (CI) = 0.43--0.97], whereas the OR was elevated among overweight or obese women (body mass index >26) (OR = 1.36; 95% CI = 0.95--1.93). Using average-weight women who did not take periconceptional multivitamins as the reference group, periconceptional multivitamin use was associated with a reduced OR for isolated heart defects among average-weight women (OR = 0.61, 95% CI = 0.36--0.99) and underweight women but not among overweight or obese women (OR = 1.69, 95% CI = 0.69--3.84).     

Maternal diet and the risk of hypospadias and cryptorchidism in the offspring

Male genital tract birth defects have been associated in previous studies with several prenatal exposures to environmental and dietary risk factors. The purpose of this study was to explore the association between hypospadias and cryptorchidism, and the dietary habits of an agricultural population in Italy. A population-based case-control study was conducted in the Sicilian Province of Ragusa. Cases (n = 90) and controls (n = 202) included births for the period 1998-2002. Data on dietary habits of the mothers, as well as health-related social, occupational and environmental exposures prior to and during the index birth, were collected through interviews. Adjusted odds ratios (OR) were calculated by logistic regression after adjustment for confounding variables. Increased ORs were observed for mothers of children with hypospadias who, during pregnancy, frequently consumed fish (OR = 2.33 [95% confidence interval (CI) 1.03, 5.31]) and market-purchased fruit (OR = 5.10 [95% CI 1.31, 19.82]). For cryptorchidism, increased risk was observed in mothers consuming liver (OR = 5.21 [95% CI 1.26, 21.50]), and smoked products (OR = 2.46 [95% CI 1.15, 5.29]). For the two malformations pooled together, increased risk was associated with maternal consumption of liver (OR = 4.38 [95% CI 1.34, 14.26]) and with frequent consumption of wine (OR = 1.98 [95% CI 1.01, 3.86]). This study suggests that some maternal dietary factors may play a role in the development of congenital defects of the male reproductive tract. In particular, our data indicate that further research may be warranted on the endocrine-disrupting effects resulting from the bioaccumulation of contaminants (fish, liver), pesticides (marketed fruit, wine) and/or potentially toxic food components (smoked products, wine, liver).     

1009例婴幼儿先天性心脏病危险因素的病例对照研究

目的 探讨母亲围孕期危险因素暴露与婴幼儿先天性心脏病的发病风险。方法 病例选择2012年3月1日~2013年10月1日在西京医院经超声心动图检查确诊为先天性心脏病的婴幼儿,对照选择为同期做超声心动图未发生先天性心脏病的婴幼儿。对病例组和对照组父母亲一般情况、母亲孕期环境因素暴露情况进行问卷调查。结果 435例先天性心脏病的婴幼儿和574例未发生先天性心脏病的婴幼儿的父母亲基本情况及母亲围孕期相关危险因素分析结果显示,母亲怀孕早期服用药物（OR=4.65,95%CI:2.84~7.66）、病毒感染（OR=3.15,95%CI:1.66~6.01）、房屋装修（OR=1.87,95%CI:1.24~2.80）、染发烫发（OR=2.18,95%CI:1.37~3.49）、父母工作环境污染暴露（OR=2.88,95%CI:1.86~4.47）均是造成心血管畸形的独立危险因素。随着暴露因素的增多,先天性心脏病发病的危险程度显著增加。当孕期同时受到3种或3种以上危险因素的暴露时,婴幼儿罹患先天性心脏病的危险性是单因素暴露的16.35倍。结论 婴幼儿先天性心脏病的发病与围孕期危险因素的暴露存在相关性。     

Parental occupational exposure to pesticides and the risk of childhood leukemia in Costa Rica

OBJECTIVES: Parental exposure to pesticides and the risk of leukemia in offspring were examined in a population-based case-control study in Costa Rica. METHODS: All cases of childhood leukemia (N=334), in 1995-2000, were identified at the Cancer Registry and the Children's Hospital. Population controls (N=579) were drawn from the National Birth Registry. Interviews of parents were conducted using conventional and icon-based calendar forms. An exposure model was constructed for 25 pesticides in five time periods. RESULTS: Mothers' exposures to any pesticides during the year before conception and during the first and second trimesters were associated with the risk [odds ratio (OR) 2.4, 95% confidence interval (95% CI) 1.0-5.9; OR 22, 95% CI 2.8-171.5; OR 4.5, 95% CI 1.4-14.7, respectively] and during anytime (OR 2.2, 95% CI 1.0-4.8). An association was found for fathers' exposures to any pesticides during the second trimester (OR 1.5, 95% CI 1.0-2.3). An increased risk with respect to organophosphates was found for mothers during the first trimester (OR 3.5, 95% CI 1.0-12.2) and for fathers during the year before conception and the first trimester (OR 1.5, 95% CI 1.0-2.2 and OR 1.6, 95% CI 1.0-2.6, respectively), and benzimidazoles during the first, second, and third trimesters of pregnancy (OR 2.2, 95% CI 1.0-4.4; OR 2.2, 95% CI 1.0-5.0; OR 2.2, 95% CI 1.0-5.2, respectively). There was a suggestion of an exposure-response gradient for fathers as regards picloram, benomyl, and paraquat. Age at diagnosis was positively associated with fathers' exposures and inversely associated with mothers' exposures. CONCLUSIONS: The results suggest that parental exposure to certain pesticides may increase the risk of leukemia in offspring.     

Respiratory symptoms: associations with pesticides, silos, and animal confinement in the Iowa Farm Family Health and Hazard Surveillance Project

BACKGROUND: Farmers are at risk for airways diseases resulting from exposures which include organic agents and chemicals on the farm. Few data on airways disease and farm exposures are available from population-based studies. The Iowa Farm Family Health and Hazard Surveillance Project provided the opportunity to assess associations between symptoms of airway disease and several farm exposures, including pesticides, grain dust, animal confinement, and exposures from silos, in a population-based study. METHODS: A stratified two-stage cluster sample was used to provide a representative farmer sample from the state. Participants provided questionnaire responses concerning demographic, respiratory symptoms, smoking, and exposure information. Associations between farm exposures and airways disease symptoms were assessed in the 385 farmer participants using chi(2) analysis and logistic regression analysis adjusting for age and smoking. RESULTS: The most frequently reported respiratory symptoms were flu-like symptoms in connection with dusty work (22%), dyspnea (21%), and phlegm (15%). Current smoking was uncommon (13%). Among farmers, applying pesticides to livestock was associated with significantly increased odds of phlegm (OR = 1.91, 95% CI 1.02-3.57), chest ever wheezy (OR = 3.92, 95% CI 1.76-8.72), and flu-like symptoms (OR = 2.93, 95% CI 1.69-5.12) in models adjusting for age and smoking. Conventional vertical silos were significantly associated with increased odds of chest ever wheezy (OR = 2.75, 95% CI 1.23-6.12) and flu-like symptoms (OR = 2.40, 95% CI 1.31-4.37). There were also significant associations between several respiratory symptoms and the presence of animal confinement facilities on the farm. CONCLUSIONS: The association between insecticide application to livestock and symptoms of airways disease is a new finding that could lead to further study of specific airway responses and exposures associated with this practice. Results confirming associations between respiratory symptoms and conventional vertical silos may be important in future studies aimed at prevention and control of exposures in those farm buildings.     

An exploratory analysis of the effect of pesticide exposure on the risk of spontaneous abortion in an Ontario farm population

The toxicity of pesticides on human reproduction is largely unknown--particularly how mixtures of pesticide products might affect fetal toxicity. The Ontario Farm Family Health Study collected data by questionnaire on the identity and timing of pesticide use on the farm, lifestyle factors, and a complete reproductive history from the farm operator and eligible couples living on the farm. A total of 2,110 women provided information on 3,936 pregnancies, including 395 spontaneous abortions. To explore critical windows of exposure and target sites for toxicity, we examined exposures separately for preconception (3 months before and up to month of conception) and postconception (first trimester) windows and for early (< 12 weeks) and late (12-19 weeks) spontaneous abortions. We observed moderate increases in risk of early abortions for preconception exposures to phenoxy acetic acid herbicides [odds ratio (OR) = 1.5; 95% confidence interval (CI), 1.1-2.1], triazines (OR = 1.4; 95% CI, 1.0-2.0), and any herbicide (OR = 1.4; 95% CI, 1.1-1.9). For late abortions, preconception exposure to glyphosate (OR = 1.7; 95% CI, 1.0-2.9), thiocarbamates (OR = 1.8; 95% CI, 1.1-3.0), and the miscellaneous class of pesticides (OR = 1.5; 95% CI, 1.0-2.4) was associated with elevated risks. Postconception exposures were generally associated with late spontaneous abortions. Older maternal age (> 34 years of age) was the strongest risk factor for spontaneous abortions, and we observed several interactions between pesticides in the older age group using Classification and Regression Tree analysis. This study shows that timing of exposure and restricting analyses to more homogeneous endpoints are important in characterizing the reproductive toxicity of pesticides.     

Persistent chlorinated pesticides and intra-uterine foetal growth retardation: a possible association

OBJECTIVE: To examine the association between DDT (dichlorodiphenyl trichloroethane) and HCH (hexachlorocyclohexane) exposure and intra-uterine growth retardation (IUGR, <10th percentile of birth weight for gestational age). METHOD: We detected p,p'-DDT, o,p'-DDT, p,p'-DDD, p,p'-DDE and alpha-HCH, beta-HCH, gamma-HCH, delta-HCH in maternal blood, placenta and cord blood, collected at parturition, from mothers with IUGR babies ( n=30) and from those with babies of normal weight ( n=24), using gas-liquid chromatography equipped with electron capture detector ((63)Ni). The adjusted odds ratios (ORs) for these pesticides in mothers and infants were determined by multiple logistic regression. RESULTS: There were statistically significant associations ( P<0.05) between maternal blood levels of alpha-HCH (OR=1.22; 95% CI: 1.02-1.46), gamma-HCH (OR=1.38; 95%CI: 1.05-1.80), delta-HCH (OR=1.61; 95% CI: 1.01-2.54), total HCH (OR=1.07; 95% CI: 1.01-1.13) and p,p'-DDE (OR=1.21; 95%CI:1.03-1.42) and IUGR after adjustment for potential confounders. Also, significant association (P<0.05) between cord blood levels of gamma-HCH (OR=1.14; 95% CI: 1.00-1.31), delta-HCH (OR=1.31; 95% CI: 1.00-1.75), total HCH (OR=1.07; 95% CI: 1.00-1.14) and IUGR were found after adjustment for potential confounders. A significant negative correlation between body weight of newborn babies and p,p'-DDE in maternal blood (r= -0.25; P<0.05) and delta-HCH and p,p'-DDE in the cord blood (r= -0.27 and -0.26; P<0.05) was noticed after gestational age had been accounted for. CONCLUSION: Exposure of pregnant women to organochlorine pesticides may increase the risk of IUGR, which is a contributing factor for infant mortality in India.     

Pesticides associated with wheeze among commercial pesticide applicators in the Agricultural Health Study

Pesticides are potential risk factors for respiratory disease among farmers, but farmers are also exposed to other respiratory toxicants. To explore the association of pesticides with wheeze in a population without other farming exposures, the authors analyzed data from 2,255 Iowa commercial pesticide applicators enrolled in the Agricultural Health Study. Controlling for age, smoking status, asthma and atopy history, and body mass index, the authors calculated odds ratios for the relationship between wheeze and 36 individual pesticides participants had used during the year before enrollment (1993-1997). Eight of 16 herbicides were associated with wheeze in single-agent models; however, the risk was almost exclusively associated with the herbicide chlorimuron-ethyl (odds ratio (OR) = 1.62, 95% confidence interval (CI): 1.25, 2.10). Inclusion of chlorimuron-ethyl in models for the other herbicides virtually eliminated the associations. The odds ratios for four organophosphate insecticides (terbufos, fonofos, chlorpyrifos, and phorate) were elevated when these chemicals were modeled individually and remained elevated, though attenuated somewhat, when chlorimuron-ethyl was included. The association for dichlorvos, another organophosphate insecticide, was not attenuated by chlorimuron-ethyl (OR = 2.48, 95% CI: 1.08, 5.66). Dose-response trends were observed for chlorimuron-ethyl, chlorpyrifos, and phorate; the strongest odds ratio was for applying chlorpyrifos on more than 40 days per year (OR = 2.40, 95% CI: 1.24, 4.65). These results add to the emerging literature linking organophosphate insecticides and respiratory health and suggest a role for chlorimuron-ethyl.     

先天性泌尿生殖系统结构畸形危险因素的研究

目的：探讨有关因素在先天性泌尿生系统结构畸形发病中的作用。方法：采用成组匹配的病列对照研究方法。对95例患先天性泌尿生殖系统 的围产儿和160例对照围产儿及其父母的情况进行调查。采用非条件logistic回归模型进行多因素分析,计算OR值及OR的95％可信限。结果：先天性泌尿生殖系统结构畸形多发生于男性围产儿（性别成比为74．7％,X^2＝74．863,P＝0．001）,多元逐步回归分析表明：母亲孕早、中期感冒（OR＝7．034,95％CI＝3．488－14．187）、低出生体重（OR＝4．075,95％CI＝1．774－9．362）、孕次≥2（OR＝3．133,95％CI＝1．514－6．483）及母亲孕前职业性接触有害化学物质（OR＝10．496,95％CI＝1．053－104．651）为先天性泌尿生殖系统结构畸形的危险因素,结论：胎儿男性别,母亲孕早、中期感冒、低出生体重,母亲孕次≥2及孕前职业性接触有害化学物质与胎儿发生先天性泌尿生系统畸形有关联。     

Maternal occupational risk factors for oral clefts. Occupational Exposure and Congenital Malformation Working Group

OBJECTIVES: This study investigated the role of maternal exposures at work during pregnancy in the occurrence of oral clefts. METHODS: The occupational exposures of 851 women (100 mothers of babies with oral clefts and 751 mothers of healthy referents) who worked during the first trimester of pregnancy were studied. All the women were part of a multicenter European case-referent study conducted using 6 congenital malformation registers between 1989 and 1992. In each center, the mother's occupational history, obtained from an interview, was reviewed by industrial hygienists who were blinded to the subject's status and who assessed the presence of chemicals and the probability of exposure. Odds ratios (OR) were estimated by a multivariate analysis including maternal occupation or occupational exposures during the first trimester of pregnancy and possible confounding factors such as center of recruitment, maternal age, urbanization, socioeconomic status, and country of origin. RESULTS: After adjustment for confounding factors, cleft palate only was significantly associated with maternal occupation in services such as hairdressing [OR 5.1, 95% confidence interval (95% CI) 1.0-26.0] and housekeeping (OR 2.8, 95% CI 1.1-7.2). The analysis suggests that the following occupational exposures are associated with orofacial clefts: aliphatic aldehydes (OR 2.1, 95% CI 0.8-5.9) and glycol ethers (OR 1.7, 95% CI 0.9-3.3) for cleft lip with or without cleft palate and lead compounds (OR 4.0, 95% CI 1.3-12.2), biocides (OR 2.5, 95% CI 1.0-6.0), antineoplastic drugs (OR 5.0, 95% CI 0.8-34.0), trichloroethylene (OR 6.7, 95% CI 0.9-49.7), and aliphatic acids (OR 6.0, 95% CI 1.5-22.8) for cleft palate only. CONCLUSIONS: Due to the limited number of subjects, these results must be interpreted with caution. However, they point out some chemicals already known or suspected as reproductive toxins.     

Maternal reproductive history and the risk of isolated congenital malformations

We examined the relationship between maternal reproductive history and the newborn's risk of isolated congenital malformations in a large case-control cohort from the Polish Registry of Congenital Malformations. Congenital malformations were classified into four categories: isolated congenital heart defects (n=1673), isolated cleft palate (n=255), cleft lip with or without cleft palate (n=448) and renal agenesis (n=103). The case groups were compared with a shared group of 2068 controls recruited in the same time period and geographic area. Multivariable logistic regression was used to assess the risk associated with maternal gravidity and of previous miscarriages after accounting for maternal age and other potential risk factors. In unadjusted analyses, maternal gravidity was significantly associated with increased risk of all four classes of congenital malformations. After adjustment, a significant association persisted for congenital heart defects [odds ratio (OR)=1.22, [95% confidence interval (CI) 1.09, 1.36], P=0.0007] and cleft lip with or without cleft palate (OR=1.21, [95% CI 1.09, 1.36], P=0.0005). A similar trend existed for isolated cleft palate (OR=1.18, [95% CI 1.02, 1.37], P=0.03). There was no appreciable increase in the risk of congenital malformations associated with a maternal history of miscarriages, but a trend for a protective effect on the occurrence of cleft lip with or without cleft palate was observed (OR=0.72, [95% CI 0.52, 0.99], P=0.045). Based on our data, maternal gravidity represents a significant risk factor for congenital heart defects and cleft lip with or without cleft palate in the newborn infant. Our data do not support an increase in risk because of past history of miscarriages.     

Birth defects risk associated with maternal sport fish consumption: potential effect modification by sex of offspring

Contaminated sport fish consumption may result in exposure to various reproductive and developmental toxicants, including pesticides and other suspected endocrine disruptors. We investigated the relation between maternal sport fish meals and risk of major birth defects among infants born to members of the New York State (NYS) Angler Cohort between 1986 and 1991 (n=2237 births). Birth defects (n=125 cases) were ascertained from both newborn medical records and the NYS Congenital Malformations Registry. For sport fish meals eaten during pregnancy, the odds ratio (OR) for all major malformations combined was slightly elevated for < or =1 meal/month (OR=1.26, 95% confidence interval (CI): 0.84, 1.89) and > or =2 meals/month (OR=1.51, CI=0.74, 3.09), with no meals during pregnancy as the reference category. Higher ORs were consistently observed among male offspring compared with females. For > or =2 meals/month, the risk for males was significantly elevated (males: OR=3.01, CI: 1.2, 7.5; females: OR=0.73, CI: 0.2, 2.4). Exposure during pregnancy and effect modification by infants sex could be important considerations for future studies of birth outcomes associated with endocrine disruptors.     

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.     

Maternal obesity and infant heart defects

OBJECTIVE: This study determined whether obese women have an increased risk of cardiovascular defects in their offspring compared with average weight women. RESEARCH METHODS AND PROCEDURES: In a case-control study, prospectively collected information was obtained from Swedish medical health registers. The study included 6,801 women who had infants with a cardiovascular defect and, as controls, all delivered women (N = 812,457) during the study period (1992 to 2001). Infants with chromosomal anomalies or whose mothers had pre-existing diabetes were excluded. Obesity was defined as BMI >29 kg/m(2), and morbid obesity was defined as BMI >35 kg/m(2). Comparisons were made with average weight women (BMI = 19.8 to 26 kg/m(2)). RESULTS: In the group of obese mothers, there was an increased risk for cardiovascular defects compared with the average weight mothers [adjusted odds ratio (OR) = 1.18; 95% CI, 1.09 to 1.27], which was slightly more pronounced for the severe types of cardiovascular defects (adjusted OR = 1.23; 95% CI, 1.05 to 1.44). With morbid obesity, the OR for cardiovascular defects was 1.40 (95% CI, 1.22 to 1.64), and for severe cardiovascular defects, the OR was 1.69 (95% CI, 1.27 to 2.26). There was an increased risk for all specific defects studied among the obese women, but only ventricular septal defects and atrial septal defects reached statistical significance. DISCUSSION: In this sample, a positive association was found between maternal obesity in early pregnancy and congenital heart defects in the offspring. A suggested explanation is undetected type 2 diabetes in early pregnancy, but other explanations may exist.     

Occupational history and exposure and the risk of adult leukemia in Shanghai

PURPOSE: Evaluation of the association of selected occupational exposures with leukemia risk. METHODS: Population-based case-control study of 486 leukemia subjects and 502 healthy controls residing in Shanghai from 1987 to 1989. Adjusted odds ratios (OR) were calculated for the association between occupational factors and leukemia risk. RESULTS: Significant increase in leukemia risk was observed in chemical manufacturing industry workers (OR=3.1, 95% CI=1.0-9.8). Increased risks for leukemia were observed from self-reported exposures to benzene (OR=1.7, 95% CI=1.1-2.6), radioactive materials (OR=3.7, 95% CI=1.3-10.2), synthetic fiber dust (OR=2.0, 95% CI=1.2-3.5), and toluene (OR=1.6, 95% CI=1.0-2.5). Dose-response relations of leukemia risk was observed with the duration of exposure to benzene (OR=3.3, 95% CI=1.6-6.9 for >or=15 years exposure; p for trend<0.01), radioactive materials (OR=5.2, 95% CI=1.1-24.7 for >or=15 years exposure; p for trend=0.02), paints (OR=2.3, 95% CI=1.2-4.7 for >or=15 years exposure; p for trend=0.09), and toluene (OR=2.9, 95% CI=1.3-6.7 for >or=15 years exposure; p for trend=0.02). CONCLUSIONS: Adult leukemia risk may be associated with working in the chemical industry, and exposure to benzene, synthetic fiber dust, radioactive materials, and toluene in the study population.     

隐睾发生的危险因素研究

目的：研究隐睾发生的危险因素。方法：采用以医院为基础的1：2配比的病例对照研究方法，按统一的调查方法对99例隐睾及198例对照组面对面问卷调查。应用SAS6。12软件对所调查因素进行单因素及多因素logistic回归分析，结果：胎儿隐睾与母亲孕早期感冒伴发热（OR＝9．37，95％CI：2．25－39．09），孕期发生先兆流产（OR＝4．66，95％CI，2．02＝10．74），孕期发生先兆子痫（OR＝16．33，95％CI：1．40－191．20），父亲职业性接触农药（OR＝12．79％CI；2．90－56．43），低出生体重（OR＝5．77，95％CI：1．39－23．98），母亲怀孕年龄＜24（OR＝2．89，95％CI：1．29－4．06）呈正相关。结论：母亲孕早期感冒伴发热，孕期发生先兆流产及先兆子痫，父亲职业性接触农药，低出体重，母亲怀孕年龄＜24岁是隐睾发病的主要危险因素。