Employment status of pregnant women in central Poland and the risk of preterm delivery and small-for-gestational-age infants

BACKGROUND: Unemployment is one of the consequences of the ongoing transformation of the Polish economy. The main objective of the present study was to investigate the relationship between women's employment status and preterm delivery (PD) and/or small-for-gestational-age (SGA) infants, in Central Poland during the socio-economic transition. METHODS: The study population comprised 8% random sample of 2,080 women from the Lodz macro region who gave birth to a child during a one-year period (1996-1997). Based on the employment status, three groups were distinguished: the employed (n = 1238), the unemployed (n = 128)--women who lost their job before pregnancy (at least 12 months prior to delivery) and were actively seeking employment, and the housewives (n = 714). Women with chronic medical problems diagnosed before pregnancy were excluded from the study. RESULTS: The rates of preterm delivery were found to be 6.3%, 11.7% and 4.9%, respectively for the employed, unemployed, and housewives. After adjustment for age, marital status, education, maternal height, smoking, own apartment, presence of cervical insufficiency and uterine irritability, an excess risk of PD was observed among the unemployed women (OR = 1.92, 95% CI: 1.01-3.64). Unemployment was associated, though not significantly, with higher rates of SGA births. CONCLUSION: In Central Poland, the unemployed pregnant women are characterised by an excess risk of preterm delivery. The impact of unemployment on the community's health, which seems to be underestimated, should be given more consideration in the national and local policies for public health.     

Risk of stillbirth from occupational and residential exposures.

OBJECTIVES: To analyse the risk of stillbirth from 12 residential and occupational maternal exposures during pregnancy. METHODS: Stillbirths and neonatal deaths in 1984 within 24 hours of birth from 10 California counties were identified from death certificates. Controls were randomly selected from live births born in 1984 and frequency matched to cases by maternal age and county. Data sources included vital statistics and a self-administered postal questionnaire. Logistic regression and proportional hazards modelling were performed; the proportional hazards considered the truncated opportunity for exposure among cases. Special focus was given to two cause of deaths groups: congenital anomalies (12% of deaths) and complications of the placenta, cord, and membranes (37% of deaths). RESULTS: Occupational exposure to pesticides during the first two months of gestation was positively associated with stillbirths due to congenital anomalies (odds ratio (OR) 2.4, 95% confidence interval (95% CI) 1.0 to 5.9), and during the first and second trimesters with stillbirths due to all causes of death (risk ratios (RR) 1.3-1.4, 95% CI 1.0 to 1.7) and stillbirths due to complications of the placenta, cord, and membranes (RR 1.6-1.7, 95% CI 1.1 to 2.3). Occupational exposure to video display terminals in the third trimester was found to have a modest inverse association with stillbirths (RR 0.7, 95% CI 0.6, 0.9). Home pesticide exposure was positively associated with stillbirths due to congenital anomalies (OR 1.7, 95% CI 1.0 to 2.9). CONCLUSIONS: Occupational exposure to pesticides, especially during early pregnancy, had a clear positive association with stillbirths regardless of cause of death. Methodologically, this study of stillbirths is unique in its analysis of specific causes of death and use of time specific exposure windows.     

Maternal occupational exposure to chemical substances and the risk of infants small-for-gestational-age.

BACKGROUND: The association between maternal occupational exposure to specific chemical substances (organic solvents, carbon tetrachloride, herbicides, chlorophenols, polychlorinated biphenyls, aromatic amines, lead and lead compounds, mercury and mercury compounds) and birth of small-for-gestational-age (SGA) infants was evaluated using data from a prospective cohort study of 3,946 pregnant women in West Germany from 1987 to 1988. METHODS: Occupational, medical, and psychosocial information was gathered through a questionnaire from pregnant women who were recruited between 15 and 28 gestational weeks. Exposure to chemical substances at the current workplace was assessed by a job-exposure matrix constructed by Pannett in 1985 and weighted for the number of working hours per week. Women not working at the time of the interview, women with multiple births, and women with stillbirths were excluded from analysis. Data were analyzed using dichotomous and polytomous logistic regression to control for age, smoking status, alcohol consumption, body mass index, and number of former births. RESULTS: The results of the dichotomous logistic regression analysis suggest that leather work might be associated with the birth of infants small-for-gestational-age through exposure to chlorophenols (P = 0.02) and aromatic amines (P = 0.05). In the polytomous logistic regression analysis, only the association between exposure to mercury and growth retardation reached statistical significance (P = 0.02); however, the power of the study is limited. Further adjustment for income, shift work, and heavy physical work had no substantial effect on the results. CONCLUSIONS: These findings suggest that maternal exposure to specific chemicals at work may be a risk factor for the birth of SGA infants.     

Atrazine in municipal drinking water and risk of low birth weight, preterm delivery, and small-for-gestational-age status

Background: Atrazine is a herbicide used extensively worldwide. Bioassays have shown that it is embryotoxic and embryolethal. Evidence of adverse reproductive outcomes from exposure in the general population is sparse.

Aims: To evaluate the association between atrazine levels in municipal drinking water and the following adverse reproductive outcomes: increased risk of preterm delivery, low birth weight (LBW), and small-for-gestational-age (SGA) status.

Methods: A total of 3510 births that took place from 1 October 1997, to 30 September 1998 were analysed. Atrazine measurements were available for 2661 samples from water treatment plants over the past decade. A seasonal pattern was identified, with atrazine peaking from May to September. The geometric mean of the atrazine level for this period was calculated for each water distribution unit and merged with the individual data by municipality of residence.

Results: Atrazine levels in water were not associated with an increased risk of LBW or SGA status and were slightly associated with prematurity. There was an increased risk of SGA status in cases in which the third trimester overlapped in whole or in part with the May–September period, compared with those in which the third trimester occurred totally from October to April (OR = 1.37, 95% CI 1.04 to 1.81). If the entire third trimester took place from May to September, the OR was 1.54 (95% CI 1.11 to 2.13).

Conclusions: Low levels of atrazine, a narrow exposure range, and limitations in the exposure assessment partly explain the lack of associations with atrazine. Findings point to the third trimester of pregnancy as the potential vulnerable period for an increased risk of SGA birth. Exposures other than atrazine and also seasonal factors may explain the increased risk.

     

Association of periconceptional multivitamin use and risk of preterm or small-for-gestational-age births

The authors' objective was to determine the relation between periconceptional multivitamin use and the risk of small-for-gestational-age (SGA: <5th percentile; 5th-<10th percentiles) or preterm (<34 weeks; 34-<37 weeks) births. Women in the Pregnancy Exposures and Preeclampsia Prevention Study (1997-2001) reported at enrollment their regular multivitamin use in the past 6 months (n=1,823). Women were classified as users or nonusers in multinomial logistic models. After adjustment for race, age, education, enrollment gestational age, and household density, periconceptional multivitamin use was associated with a reduced risk of preterm births (<34 weeks) (odds ratio (OR)=0.29, 95% confidence interval (CI): 0.13, 0.64) and spontaneous preterm births (<34 weeks) (OR=0.40, 95% CI: 0.16, 0.99). Risk of SGA (<5th percentile) was marginally lower (OR=0.64, 95% CI: 0.40, 1.03) after adjustment for smoking, education, parity, enrollment gestational age, and body mass index. Prepregnancy body mass index modified this relation. Nonobese users had a reduction (OR=0.54, 95% CI: 0.32, 0.91) in risk of SGA (<5th percentile); there was no effect among obese women. There was no effect of multivitamin use on risk of preterm births (34-<37 weeks) or SGA (5th-<10th percentiles). Sensitivity analysis for unmeasured confounding by folate intake supported these findings. Study results indicate lower rates of severe preterm births and extreme SGA in women who report periconceptional vitamin use, although these should be considered cautiously until replicated.     

急诊护士血源性职业暴露状况及风险防范

目的 了解急诊护士在急救护理过程中发生血源性职业暴露状况,进行相关分析,为血源性职业暴露风险提出防范策略.方法 对2007年7月-2010年8月医院急诊护士血源性职业暴露143人进行回顾性调查.结果 143例急诊护士血源性职业暴露以1～5年护龄的护上比例最高,占43.35％;最易发生暴露的环节是拔针及拔针后处置,为46.15％;暴露的方式以锐器伤为主,占74.13％;最常见的暴露源是HBV;发生暴露的局部处理率100.00％;暴露后采取及时、合理的处置及预防措施,143人追踪检测无相关疾病感染.结论 血源性职业暴露是急诊护士面临的高危职业风险,应加强职业防护的培训,降低职业暴露的风险.     

早产及其相关危险因素的研究

目的:探讨早产及其相关危险因素。方法:纵向随访研究,通过面对面问卷调查,收集妊娠妇女背景资料、孕期个人行为习惯、社会环境因素、妊娠期健康状况等相关信息,随访至分娩,收集妊娠结局资料。数据采用多因素Logistic回归分析方法。结果:711例调查对象中,早产117例(16.46%),发生率较既往报道高。未发现妊娠期个人行为习惯与早产的关系,但年龄增长、工作噪音和胎膜早破与早产明显有关,OR分别为1.43(95%CI:1.05~1.94)、3.38(95%C I:1.21~9.39)、2.14(95%C I:1.19~3.83)。结论:面对早产的高发生率,不应忽略社会环境的潜在影响。对外来务工的妊娠妇女,孕期保健时应常规询问职业状况等因素,以及时发现不利影响,给予适当帮助和指导。     

Maternal asthma and risk of preterm delivery

PURPOSE: We studied the relation between maternal history of asthma and preterm delivery. METHODS: The 312 preterm delivery cases, studied in aggregate, and in subgroups (spontaneous preterm labor, preterm premature rupture of membranes, medically induced preterm delivery), were compared with 424 randomly selected women who delivered at term. Maternal medical records provided information on maternal lifetime asthma status, pregnancy outcome, and sociodemographic characteristics. Using multivariate logistic regression, we derived maximum likelihood estimates of adjusted odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Maternal history of asthma was associated with an increased risk of preterm delivery overall (OR = 2.37; 95% CI 1.15-4.88). Analyses of preterm delivery sub-groups indicated that maternal history of asthma was associated with at least a doubling in risk of spontaneous preterm labor (OR = 2.35; 95% CI 0.84-6.58) and medically induced preterm delivery (OR = 2.69; 95% CI 1.11-6.53), though only the latter approached statistical significance. There was some evidence of a modest association between maternal asthma and risk of preterm premature rupture of membranes (OR = 1.63; 95% CI 0.50-5.33). CONCLUSIONS: These results support the hypothesis that maternal asthma is associated with an increased risk of preterm labor and delivery.     

Airborne occupational exposures and risk of oesophageal and cardia adenocarcinoma

Background

The reasons for the increasing incidence of and strong male predominance in patients with oesophageal and cardia adenocarcinoma remain unclear. The authors hypothesised that airborne occupational exposures in male dominated industries might contribute.

Methods

In a nationwide Swedish population based case control study, 189 and 262 cases of oesophageal and cardia adenocarcinoma respectively, 167 cases of oesophageal squamous cell carcinoma, and 820 frequency matched controls underwent personal interviews. Based on each study participant''s lifetime occupational history the authors assessed cumulative airborne occupational exposure for 10 agents, analysed individually and combined, by a deterministic additive model including probability, frequency, and intensity. Furthermore, occupations and industries of longest duration were analysed. Relative risks were estimated by odds ratios (OR), with 95% confidence intervals (CI), using conditional logistic regression, adjusted for potential confounders.

Results

Tendencies of positive associations were found between high exposure to pesticides and risk of oesophageal (OR 2.3 (95% CI 0.9 to 5.7)) and cardia adenocarcinoma (OR 2.1 (95% CI 1.0 to 4.6)). Among workers highly exposed to particular agents, a tendency of an increased risk of oesophageal squamous cell carcinoma was found. There was a twofold increased risk of oesophageal squamous cell carcinoma among concrete and construction workers (OR 2.2 (95% CI 1.1 to 4.2)) and a nearly fourfold increased risk of cardia adenocarcinoma among workers within the motor vehicle industry (OR 3.9 (95% CI 1.5 to 10.4)). An increased risk of oesophageal squamous cell carcinoma (OR 3.9 (95% CI 1.2 to 12.5)), and a tendency of an increased risk of cardia adenocarcinoma (OR 2.8 (95% CI 0.9 to 8.5)), were identified among hotel and restaurant workers.

Conclusions

Specific airborne occupational exposures do not seem to be of major importance in the aetiology of oesophageal or cardia adenocarcinoma and are unlikely to contribute to the increasing incidence or the male predominance.     

早期肠胃营养对于小于胎龄儿宫外生长发育的影响

目的：探讨早期肠内营养联合肠外营养支持对小于胎龄儿（ SGA）宫外生长发育的影响。方法选取2011至2014年温州市中心医院出生的SGA患儿90例,按照胎龄及出生体重分组：①胎龄分组：≥37周组12例及＜37周组78例;②出生体重分组：≥2．5 kg组36例及＜2．5 kg组54例,均接受早期肠内营养联合肠外营养支持治疗,监测生化指标、体重、头围及恢复出生体重时间;统计宫外发育迟缓（ EUGR）的发生率;评价患儿喂养的耐受情况。结果①不同出生体重组：总胆红素（ TBIL）、胆固醇（CH）、甘油三酯（TG）及尿素氮（BUN）、头围及体重增长情况的差异无统计学意义（t值分别为9．009、9．435、9．221、9．758、10．297、9．502,均P＞0．05）;出生体重≥2．5kg组的恢复出生体重时间（t＝6．663,P＜0．05）及EUGR发生率均显著下降,两组比较差异有统计学意义（χ2＝5．632,P＜0．05）;②不同胎龄组：生化指标（TBIL、CH、TG、BUN）及EUGR的发生率比较,差异无统计学意义（t值分别为11．039、11．445、10．280、10．775,（χ2＝11．457,均P＞0．05）;与胎龄＜37周组相比较,胎龄≥37周组头围及体重增长速度增加,恢复至出生体重的时间显著缩短,两组比较差异有统计学意义（ t值分别为5．647、4．090、3．677,均P＜0．05）;③所有病例无喂养不耐受情况发生。结论早期肠内营养联合肠外营养支持有助于改善SGA的宫外生长发育情况。     

Maternal fish consumption, mercury levels, and risk of preterm delivery

BACKGROUND: Pregnant women receive mixed messages about fish consumption in pregnancy because unsaturated fatty acids and protein in fish are thought to be beneficial, but contaminants such as methylmercury may pose a hazard. METHODS: In the Pregnancy Outcomes and Community Health (POUCH) study, women were enrolled in the 15th to 27th week of pregnancy from 52 prenatal clinics in five Michigan communities. At enrollment, information was gathered on amount and category of fish consumed during the current pregnancy, and a hair sample was obtained. A segment of hair closest to the scalp, approximating exposure during pregnancy, was assessed for total mercury levels (70-90% methylmercury) in 1,024 POUCH cohort women. RESULTS: Mercury levels ranged from 0.01 to 2.50 pg/g (mean = 0.29 microg/g; median = 0.23 microg/g). Total fish consumption and consumption of canned fish, bought fish, and sport-caught fish were positively associated with mercury levels in hair. The greatest fish source for mercury exposure appeared to be canned fish. Compared with women delivering at term, women who delivered before 35 weeks' gestation were more likely to have hair mercury levels at or above the 90th percentile (> or = 0.55 microg/g), even after adjusting for maternal characteristics and fish consumption (adjusted odds ratio = 3.0; 95% confidence interval, 1.3-6.7). CONCLUSION: This is the first large, community-based study to examine risk of very preterm birth in relation to mercury levels among women with low to moderate exposure. Additional studies are needed to see whether these findings will be replicated in other settings.     

Free amino acids in preterm and term milk from mothers delivering appropriate- or small-for-gestational-age infants

Free amino acids were quantitated in human milk collected during the first month postpartum from mothers of appropriate preterm (26-32 and 33-36 wk gestation) and term (small or appropriate-for-gestational-age) infants. Glutamic acid and taurine were the most abundant amino acids in all four groups at all stages of lactation. The ratio of essential to nonessential amino acids was higher in colostrum than in mature milk although the total amino acid level of mature milk was double that of the colostrum. Nonprotein amino acids amount to approximately 40% of the free-amino acid pool in colostrum. Differences in the content and changes in free-amino acid levels during lactation among the groups were observed.     

Work-related physical exertion and risk of preterm, low birthweight delivery

Although many women work during pregnancy, the effect of maternal job experience on pregnancy outcome is controversial. We investigated whether work-related physical exertion increases a woman's risk of delivering a preterm, low birthweight infant. We studied 773 employed, pregnant women included in the National Longitudinal Survey of Labor Market Experience, Youth Cohort (NLSY), a nationally representative sample of young adults. Data concerning work status, job title during pregnancy, and other factors affecting the outcome of pregnancy were obtained from the NLSY. Assessment of physical exertion was based on job title, using an established catalogue of occupational characteristics. Women in jobs characterised by high physical exertion experienced a higher rate of preterm, low birthweight delivery, defined as maternal report of delivery more than 3 weeks early and birthweight under 2,500 g (adjusted RR = 5.1, 95% CI = 1.5, 17.7). These findings support a policy of limiting work-related physical exertion during pregnancy.     

Work-related physical exertion and risk of preterm, low birthweight delivery

Summary. Although many women work during pregnancy, the effect of maternal job experience on pregnancy outcome is controversial. We investigated whether work-related physical exertion increases a woman's risk of delivering a preterm, low birthweight infant. We studied 773 employed, pregnant women included in the National Longitudinal Survey of Labor Market Experience, Youth Cohort (NLSY), a nationally representative sample of young adults. Data concerning work status, job title during pregnancy, and other factors affecting the outcome of pregnancy were obtained from the NLSY. Assessment of physical exertion was based on job title, using an established catalogue of occupational characteristics. Women in jobs characterised by high physical exertion experienced a higher rate of preterm, low birthweight delivery, defined as maternal report of delivery more than 3 weeks early and birthweight under 2 500 g (adjusted RR=5.1, 95% CI=1.5, 17.7). These findings support a policy of limiting work-related physical exertion during pregnancy.     

Incidence of and socio-demographic risk factors for stillbirth, preterm birth and low birthweight among Zimbabwean women

Data on birth outcomes are important for planning maternal and child health care services in developing countries. Only a few studies have examined frequency of birth outcomes in Zimbabwe, none of which has jointly examined the spectrum of poor birth outcomes across important demographic subgroups. We assessed delivery patterns and birth outcomes in 17 174 births over a one-year period from October 1997 to September 1998 at Harare Hospital, Zimbabwe. The annual rate of stillbirth was 61 per 1000 live births, rate of preterm birth (<37 weeks) was 168 per 1000, and low birthweight (LBW) (<2500 g) was 199 per 1000. Not attending antenatal care (prenatal care) was associated with increased risks of stillbirth [relative risk (RR) = 2.54, 95% CI 2.21, 2.92], preterm delivery [RR = 2.43, 95% CI 2.26, 2.61] and LBW births [RR = 2.16, 95% CI 2.02, 2.31]. Preterm births and LBW births were more likely to be stillborn [RR = 7.26, 95% CI 6.28, 8.39 and RR = 6.85, 95% CI 5.94, 7.91]. In conclusion, the rate of stillbirth is high and is predominantly associated with preterm births and to a lesser extent LBW. Reducing the frequency of stillbirth will require a better understanding of the determinants of preterm births and strategies for addressing this particular subset of high-risk births.     

早产危险因素的病例对照研究

目的:探索早产的危险因素。方法:采用病历记录结合问卷调查的方法,选择50个可能的危险因素,对213例早产产妇和500例非早产产妇进行比较,分析早产的危险因素。结果:单因素及多因素Logistic回归分析显示,产检8次及以上、孕期增重、前置胎盘、胎膜早破、妊娠期高血压疾病、孕前3个月被动吸烟、已生育2胎及以上、既往避孕药避孕对早产有明显的影响。结论:针对早产的危险因素,应及早采取措施,以改善早产的结局。     

Effect of different questionnaire formats on reporting of occupational exposures

During an exposure monitoring study, 78 saw maintenance tradesmen were randomly assigned to be interviewed about their exposures using one of two questionnaire formats: open-ended and partly prompted questions about five categories of materials; and detailed prompting about 75 agents. The more open-ended questionnaire elicited fewer exposure responses overall, but more responses about agents not included on the detailed questionnaire. Composite materials and trade name products were more frequently cited as exposures than individual metals or compounds. Validity of responses was ascertained using air measurements (individual metals) or observations of the employees (composite materials). Sums of sensitivities and specificities were very low (near 1.0) for most of the metals for both types of questionnaire. For composite materials, validity improved substantially. Sensitivities with the partly prompted format (0.44–0.85) were always lower than with detailed prompting (0.80–1.00). Specificities were usually, but not always, higher with partial prompting (0.66–0.92) than with detailed prompting (0.18–0.86). Selection of questionnaire format for an epidemiologic study would depend on the likely prevalence of exposure in controls and the effects of trade-offs in sensitivity and specificity.     

Parental occupational exposures and risk of childhood cancer: a review

We reviewed the literature in order to summarize the present knowledge on the association between parental occupational exposures to chemicals and the risk of childhood malignancy. The 32 studies pertaining to this topic were evaluated by considering various study qualities such as sample size, specificity of outcome, confounding, exposure specificity, and control selection. When evaluating the findings from any epidemiologic study, the potential sources of bias have to be considered. The selection of subjects, misclassification of exposure or outcome, and confounding from extraneous factors can contribute to a biased estimate of effect. Studies done to minimize these potential biases will be more valid, and these studies should be given the most weight when parental occupational exposures are evaluated as risk factors for childhood malignancy. We conclude that the preponderance of evidence supports the hypothesis that occupational exposure of parents to chemicals increases the risk of childhood malignancy. The parental occupational exposures implicated in childhood malignancy risk are exposure to chemicals including paints, petroleum products, solvents (especially chlorinated hydrocarbons) and pesticides, and exposure to metals. The available data do not allow the identification of specific etiologic agents within these categories of compounds. Future epidemiologic and toxicologic studies should be designed to pursue these leads.