During 1992-1995, 430 Danish couples were recruited after a nationwide mailing of a letter to 52,255 trade union members who were 20-35 years old, lived with a partner, and had no children. The couples were enrolled into the study when they discontinued birth control, and they were followed for six menstrual cycles or until a clinically recognized pregnancy. At enrollment and each month throughout the follow-up, both partners completed a questionnaire that asked them about their smoking, alcohol consumption, and intake of caffeinated beverages. The effect of current smoking and smoking exposure in utero was evaluated by using a logistic regression model with pregnancy outcome of each cycle in a Cox discrete model calculating the fecundability odds ratio. After adjustment for female body mass index and alcohol intake, diseases in female reproductive organs, semen quality, and duration of menstrual cycle, the fecundability odds ratio for smoking women exposed in utero was 0.53 (95% confidence interval (CI) 0.31-0.91) compared with unexposed nonsmokers. Fecundability odds ratio for nonsmoking women exposed in utero was 0.70 (95% CI 0.48-1.03) and that for female smokers not exposed in utero was 0.67 (95% CI 0.42-1.06). Exposure in utero was also associated with a decreased fecundability odds ratio in males (0.68, 95% CI 0.48-0.97), whereas present smoking did not reduce fecundability significantly. It seems advisable to encourage smoking cessation prior to the attempt to conceive as well as during pregnancy.
OBJECTIVES: The aim of the study was to investigate reproductive outcomes such as birthweight, preterm births, and postterrm births among women working in research laboratories while pregnant. METHODS: Female university personnel were identified from a source cohort of Swedish laboratory employees, and the database was linked to the medical birth register. The first births of the women were included in the analysis, 249 pregnancies among the women with laboratory work and 613 pregnancies among the women without laboratory tasks. Information about exposure to various laboratory agents was obtained from a previous questionnaire investigation at the research group level according to a specific definition. The ponderal index and ratio between observed and expected birthweights were calculated. Logistic regression models were used for analyses of dichotomous outcomes (preterm, postterrm and birthweight). RESULTS: Exposure to laboratory work with solvents was associated with an increased risk of preterm births, the estimated odds ratio (OR) being 3.4 (1.0
The hypothesis that exposure to traffic-related air pollution increases the risk of developing cancer during childhood was investigated. The authors enrolled 1,989 children reported to the Danish Cancer Registry with a diagnosis of leukemia, tumor of the central nervous system, or malignant lymphoma during 1968-1991 and 5,506 control children selected at random from the entire childhood population. The residential histories of the children were traced from 9 months before birth until the time of diagnosis of the cases and a similar period for the controls. For each of the 18,440 identified addresses, information on traffic and the configuration of streets and buildings was collected. Average concentrations of benzene and nitrogen dioxide (indicators of traffic-related air pollution) were calculated for the relevant period, and exposures to air pollution during pregnancy and during childhood were calculated separately. The risks of leukemia, central nervous system tumors, and all selected cancers combined were not linked to exposure to benzene or nitrogen dioxide during either period. The risk of lymphomas increased by 25% (p for trend = 0.06) and 51% (p for trend = 0.05) for a doubling of the concentration of benzene and nitrogen dioxide, respectively, during the pregnancy. The association was restricted to Hodgkin's disease.
The incidence of allergic diseases was studied in the children living in an oil-extracting region of the Republic of Udmurtia. A hygienic assessment of the level of environmental pollution was made in the study areas. The increased atmospheric contamination was ascertained to cause an increase in the incidence of allergic diseases in children. There was a correlation between the concentration of noxious substances as part of the ambient air and the prevalence of allergic diseases in children. The studies suggest that the children living in the oil-extracting area have worse parameters of nonspecific resistance than do the control children. The findings serve as the basis for developing measure to lower environmental pollution and to reduce the incidence of allergic diseases in children.
To study the association between antibiotic intake in pregnancy and the development of otitis media and placement of ventilation tubes (VTs) in the offspring under the hypothesis that antibiotics in pregnancy may alter the offspring's propensity for disease.
Data from the 700 children in the Copenhagen Prospective Studies on Asthma in Childhood 2010 unselected birth cohort study were used. Information on maternal antibiotic use and other exposures during pregnancy was collected prospectively from interviews and validated in national registries. Otitis media episodes were registered in a prospective diary for 3 years. Information regarding children's VTs was obtained from national registries.
There were 514 children who had diary information and were included in the analysis regarding otitis media episodes. For VTs analysis, 699 children were included. Thirty-seven percent of the mothers received antibiotics during pregnancy, and this was associated with increased risk of otitis media (adjusted hazard ratio 1.30; 95% CI 1.04-1.63; P?=?.02). The risk of receiving VTs was especially associated with third trimester antibiotics (adjusted hazard ratio 1.60; 95% CI 1.08-2.36, P?=?.02). The risk of otitis media increased with increasing number of treatments (per-level adjusted hazard ratio 1.20; 95% CI 1.04-1.40; P?=?.02), but for VTs this association was not significant after adjustment.
Maternal use of antibiotics during pregnancy is associated with an increased risk of otitis media and VT insertions in the offspring. Antibiotics late in pregnancy mainly contributed to these effects, pointing toward potential transmission of an unfavorable microbiome from mother to child.
World Health Organization (WHO), in cooperation with the Consortium to Perform Human Biomonitoring on a European Scale (COPHES), has developed a standardized methodology for human biomonitoring (HBM) surveys in maternities in order to assess prenatal exposure to mercury. To test this standard methodology and adapt it to Russian settings, a cross-sectional HBM survey involving 120 parturient women was conducted in six maternities of the Moscow Region. Levels of total mercury in maternal hair (geometric mean: 0.21 µg/g, 95th percentile: 0.54 µg/g), cord blood (0.89 µg/L and 2.38 µg/L, respectively) and maternal urine (0.27 µg/L and 0.94 µg/L) in this population were similar to those in other European countries with relatively low fish consumption. Consumption of all types of fish at least once per week during the third trimester of pregnancy compared to fish consumption less than once per month was associated with the increase of geometric mean level of total mercury: in hair by 31% (95% confidence interval: 4%, 66%) higher, in cord blood--by 38% (9%, 74%) and in maternal urine--by 36% (2%, 81%). No biomarker values exceeded levels recommended by WHO or national agencies in the USA and Germany. However; at the population level, adverse effects of prenatal exposures to mercury can still be substantial.
Prenatal exposure to tobacco smoke through mother's smoking increases the risk of developing asthma later in life. A recent study suggested that this effect is present only in girls. We explored potential differences in susceptibility between boys and girls.
We followed all 58,841 Finnish singleton babies born in 1987 through 5 nationwide registries for 7 years and identified all cases of doctor-diagnosed asthma (ICD-9 code 493). The birth registry provided categorical information on the mother's smoking during pregnancy: no smoking (reference), low exposure (10 cigarettes per day).
In girls the cumulative incidence of asthma was 0.0245 in the reference group, 0.0310 in the low maternal smoking group (risk difference = 0.0065; 95% CI = 0.0053-0.0076), and 0.0360 in the high maternal smoking group (0.0115; 0.0096-0.0133). The corresponding cumulative incidences for boys were 0.0405, 0.0501 (0.0096; 0.0089-0.0103), and 0.0522 (0.0117; 0.0091-0.0142). In logistic regression analysis adjusting for confounding, the combined effect of male sex and high maternal smoking (compared with female sex and no smoking) was 112% excess risk. This corresponded closely to what would be expected from the additive independent effects of male sex (67% excess risk) and high maternal smoking (44% excess risk).
Effects of maternal smoking during pregnancy on the risk of developing asthma are similar in boys and girls, with no interaction on an additive scale.
Previous research demonstrated consistent associations between ambient air pollution and emergency room visits, hospitalizations, and mortality. Effect of air pollution on perinatal outcomes has recently drawn more attention. We examined the association between intrauterine growth restriction (IUGR) among singleton term live births and sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and fine particles (PM2.5) present in ambient air in the Canadian cities of Calgary, Edmonton, and Montreal for the period 1985-2000. Multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for IUGR, based on average daily levels of individual pollutants over each month and trimester of pregnancy after adjustment for maternal age, parity, infant gender, season, and city of residence. A 1 ppm increase in CO was associated with an increased risk of IUGR in the first (OR=1.18; 95% CI 1.14-1.23), second (OR=1.15; 95% CI 1.10-1.19) and third (OR=1.19; 95% CI 1.14-1.24) trimesters of pregnancy, respectively. A 20 ppb increase in NO2 (OR=1.16; 95% CI 1.09-1.24; OR=1.14; 95% CI 1.06--1.21; and OR=1.16; 95% CI 1.09-1.24 in the first, second, and third trimesters) and a 10 mug/m3 increase in PM2.5 (OR=1.07; 95% CI 1.03-1.10; OR=1.06; 95% CI 1.03-1.10; and OR=1.06; 95% CI 1.03-1.10) were also associated with an increased risk of IUGR. Consistent results were found when ORs were calculated by month rather than trimester of pregnancy. Our findings add to the emerging body of evidence that exposure to relatively low levels of ambient air pollutants in urban areas during pregnancy is associated with adverse effects on fetal growth.
The etiology of hypospadias is poorly understood. Exposure to pesticides has been considered a risk factor, although findings are inconsistent. Diet constitutes a significant exposure route for pesticides, and pesticide residues are more frequently reported in conventional than organic food products. We examined the association between organic dietary choice during pregnancy and presence of hypospadias in the offspring.
Mothers of 306 boys operated on for hypospadias were frequency matched for geography and child birth year to 306 mothers of healthy boys in a case-control study. Telephone interviews were conducted regarding demographic and lifestyle factors, including intake and organic choice of selected food items (milk, dairy products, egg, fruit, vegetables and meat). Logistic regression models were constructed for dietary variables, and odds ratios were calculated controlling for maternal age, body mass index and alcohol consumption.
Overall organic choice of food items during pregnancy was not associated with hypospadias in the offspring. However, frequent current consumption of high fat dairy products (milk, butter) while rarely or never choosing the organic alternative to these products during pregnancy was associated with increased odds of hypospadias (adjusted OR 2.18, 95% CI 1.09-4.36).
This large case-control study of boys operated on for hypospadias suggests an association between hypospadias in the offspring and the mother not choosing the organic alternative, and having a high current intake of nonorganic butter and cheese. This finding could be due to chemical contamination of high fat dairy products. However, general lifestyle and health behavior related to choosing organic alternatives may also explain the finding.