BACKGROUND: The effects of prenatal exposure to toxic elements on birth outcomes and child development have been an area of concern. This study aimed to assess the profile of prenatal exposure to toxic elements, arsenic (As), bismuth (Bi), cadmium (Cd), mercury (total mercury (THg), methylmercury (MHg), inorganic mercury (IHg)), lead (Pb), antimony (Sb) and tin (Sn), and essential trace elements, copper (Cu), selenium (Se) and zinc (Zn), using the maternal blood, cord blood and placenta in the Tohoku Study of Child Development of Japan (N = 594-650). METHODS: Inductively coupled plasma mass spectrometry was used to determine the concentrations of these elements (except mercury). Levels of THg and MeHg were measured using cold vapour atomic absorption spectrophotometry and a gas chromatograph-electron capture detector, respectively. RESULTS: Median concentrations (25th-75th) of As, Cd, Pb, Sb, Sn and THg in the maternal blood were 4.06 (2.68-6.81), 1.18 (0.74-1.79), 10.8 (8.65-13.5), 0.2 (0.06-0.40) and 0.2 (0.1-0.38) ng mL and 5.42 (3.89-7.59) ng g, respectively. Median concentrations (25th-75th) of As, Cd, Pb, Sb, Sn and THg in the cord blood were 3.68 (2.58-5.25), 0.53 (0.10-1.25), 9.89 (8.02-12.5), 0.39 (0.06-0.92) and 0.2 (0.2-0.38) ng mL and 9.96 (7.05-13.8) ng g, respectively. CONCLUSIONS THg and Sb levels in the cord blood were twofold higher than those in the maternal blood. Cord blood to maternal blood ratios for As, Cd and Sb widely varied between individuals. To understand the effects of prenatal exposure, further research regarding the variations of placental transfer of elements is necessary.
Adult ; Female ; Fetal Blood ; chemistry ; Humans ; Japan ; Maternal Exposure ; statistics & numerical data ; Maternal-Fetal Exchange ; Metals ; blood ; Placenta ; chemistry ; Pregnancy ; blood ; Trace Elements ; blood ; Urban Health

OBJECTIVEThe number of analyzed outcome variables is important in the statistical analysis and interpretation of research findings. This study investigated published papers in the field of environmental health studies. We aimed to examine whether differences in the number of reported outcome variables exist between papers with non-significant findings compared to those with significant findings. Articles on the maternal exposure to mercury and child development were used as examples.

METHODSArticles published between 1995 and 2013 focusing on the relationships between maternal exposure to mercury and child development were collected from Medline and Scopus.

RESULTSOf 87 extracted papers, 73 used statistical significance testing and 38 (43.7%) of these reported 'non-significant' (P>0.05) findings. The median number of child development outcome variables in papers reporting 'significant' (n=35) and 'non-significant' (n=38) results was 4 versus 7, respectively (Mann-Whitney test P-value=0.014). An elevated number of outcome variables was especially found in papers reporting non-significant associations between maternal mercury and outcomes when mercury was the only analyzed exposure variable.

CONCLUSIONAuthors often report analyzed health outcome variables based on their P-values rather than on stated primary research questions. Such a practice probably skews the research evidence.

Bias ; Child ; Child Development ; drug effects ; physiology ; Environmental Exposure ; statistics & numerical data ; Environmental Health ; statistics & numerical data ; Female ; Humans ; Maternal Exposure ; statistics & numerical data ; Mercury ; toxicity ; Outcome Assessment (Health Care) ; standards ; Periodicals as Topic ; standards ; statistics & numerical data

BACKGROUND: The Japan Environment and Children's Study (JECS) is a nation-wide birth cohort study investigating environmental effects on children's health and development. In this study, the exposure characteristics of the JECS participating mothers were summarized using two questionnaires administered during pregnancy. METHODS: Women were recruited during the early period of their pregnancy. We intended to administer the questionnaire during the first trimester (MT1) and the second/third trimester (MT2). The total number of registered pregnancies was 103,099. RESULTS: The response rates of the MT1 and MT2 questionnaires were 96.8% and 95.1%, respectively. The mean gestational ages (SDs) at the time of the MT1 and MT2 questionnaire responses were 16.4 (8.0) and 27.9 (6.5) weeks, respectively. The frequency of participants who reported "lifting something weighing more than 20 kg" during pregnancy was 5.3% for MT1 and 3.9% for MT2. The Cohen kappa scores ranged from 0.07 to 0.54 (median 0.31) about the occupational chemical use between MT1 and MT2 questionnaires. Most of the participants (80%) lived in either wooden detached houses or steel-frame collective housing. More than half of the questionnaire respondents answered that they had "mold growing somewhere in the house". Insect repellents and insecticides were used widely in households: about 60% used "moth repellent for clothes in the closet," whereas 32% applied "spray insecticide indoors" or "mosquito coil or an electric mosquito repellent mat." CONCLUSIONS We summarized the exposure characteristics of the JECS participants using two maternal questionnaires during pregnancy.
Adult ; Child Health ; Cohort Studies ; Female ; Gestational Age ; Humans ; Japan ; Maternal Exposure ; statistics & numerical data ; Mothers ; statistics & numerical data ; Pregnancy ; Surveys and Questionnaires ; Young Adult

Objective: The number of children with polydactyly is increasing. In addition to genetic factors, an influence of maternal behavior or environmental effects during pregnancy is becoming increasingly apparent. However, epidemiological data on these effects are lacking. Methods: This hospital-based, case-control study enrolled 143 infants with polydactyly and 286 controls without genetic diseases to evaluate the association between active and passive maternal smoking during pregnancy and the likelihood of giving birth to a child with polydactyly. Results: Active and passive maternal smoking during pregnancy was associated with an increased risk of giving birth to a child with polydactyly (active smoking: OR=4.74, 95%CI: 1.43-15.65, P=0.011; passive smoking: OR=2.42, 95%CI: 1.32-4.44, P=0.004). After adjusting for confounders, smoking during pregnancy remained significant influence on polydactyly (active smoking: aOR=7.27, 95%CI: 1.72-30.72, P=0.007; passive smoking: aOR=2.41, 95%CI: 1.11-5.23, P=0.026). Conclusion: Active and passive maternal smoking during pregnancy appears to be a risk factor for polydactyly in newborns.
Case-Control Studies ; Child ; Female ; Fingers/abnormalities* ; Humans ; Infant ; Infant, Newborn ; Inhalation Exposure/statistics & numerical data* ; Maternal Exposure/statistics & numerical data* ; Polydactyly/epidemiology* ; Pregnancy ; Pregnancy Complications/etiology* ; Risk Factors ; Smoking/adverse effects* ; Tobacco Smoke Pollution/statistics & numerical data*

OBJECTIVEThis paper was to analyze the difference of exposure levels of the environmental risk factors on birth defects during peri-conceptional period between intended and unintended pregnancies, and to estimate the role of intended pregnancies in reducing exposure of environmental risk factors.

METHODSData used in this paper were from a retrospective survey of maternal women from 2002 through 2004 conducted in Wuxi city. The total number of women under study was 1628. Logistic regression model was employed to control women's childbearing age and education level for analysis of the role of intended pregnancies in reducing risk of unsafe use of medicine during pregnancy, exposure to toxic substance in working or living environments and unhealthy lifestyles.

RESULTSThe proportion of intended pregnancies was 73.2%. The proportion of intended pregnancies in urban women was slightly lower than that in rural women,and the proportion of intended pregnant women whose childbearing age was over 30 years old,was significantly higher than that whose childbearing age was under 30 years old. There were significant differences in exposure risks of unsafe use of medicine and some unhealthy lifestyles between the intended and the unintended. In the intended group, the proportions of taking the suspicious teratogenic drugs and staying up were 2.5% and 2.9% respectively, significantly lower than those in unintended group whose proportion were 6.0% and 5.5%. When compared with the unintended pregnant women, the exposure risk of taking the suspicious teratogenic drugs and staying up in intended pregnant women decreased by 60% and 50% respectively.

CONCLUSIONIntended pregnancies could significantly reduce the risk of taking the suspicious teratogenic drugs and unhealthy lifestyles. Reducing the incidence of unwanted pregnancy and increasing the proportion of intended pregnancies were both cost-effective methods for preventing birth defects.

Adult ; Cross-Sectional Studies ; Family Planning Services ; Female ; Humans ; Logistic Models ; Maternal Exposure ; statistics & numerical data ; Pregnancy ; Pregnancy, Unplanned ; Retrospective Studies ; Risk Assessment ; Risk Factors

OBJECTIVETo investigate the association between ambient fine particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5) and the risk on preterm birth.

METHODSA total of 1 882 pregnant women with local residency of Taiyuan city and underwent delivery at the First Hospital of Shanxi Medical University with the dates of conception between January 1 and December 31, 2013, were enrolled in the study. Information on general demographics, home address and history on pregnancy, lifestyle and related environmental factors were collected through in-person interview. Birth outcomes and maternal complications were abstracted from medical records. Data on the amount of daily average PM2.5 from 8 monitor points in Taiyuan city, between March 1, 2012 and December 31, 2013 were also collected. Individual exposure during pregnancy were calculated using the inverse-distance weighting method, based on home address. Multivariate unconditional logistic regression model was used to examine the associations among PM2.5 exposure, risk of preterm birth and related clinical subtypes.

RESULTSThe overall incidence of preterm birth was 8.21% (151/1 839)in 1 839 pregnant women. Exposure to ambient PM2.5 during the second week prior to delivery was associated with an increased risk of preterm birth (OR=1.087, 95% CI: 1.001-1.182 per 10 μg/m(3) increase) and mild preterm birth (OR=1.099, 95% CI: 1.007-1.200 per 10 μg/m(3)). Compared to data from the China Environmental Air Quality Standard, higher level of exposure (≥75 μg/m(3)) of PM2.5 during the second week before delivery was associated with an increased risk of preterm birth (OR=1.008, 95%CI: 1.000-1.017) but the association was mainly seen for mild preterm birth (OR=1.010, 95%CI: 1.001-1.018).

CONCLUSIONSRESULTS from our study showed that exposure to high level of PM2.5 during late pregnancy would increase the risk of preterm birth. Future large studies are needed to examine the association by preterm clinical subtypes and to elucidate potential underlying mechanisms.

China ; epidemiology ; Environmental Exposure ; adverse effects ; analysis ; Female ; Humans ; Incidence ; Infant, Newborn ; Logistic Models ; Maternal Exposure ; Particle Size ; Particulate Matter ; analysis ; toxicity ; Pregnancy ; Pregnancy Complications ; Premature Birth ; chemically induced ; epidemiology ; Public Health ; statistics & numerical data

BACKGROUND: The majority of studies linking exposure to metals with certain health outcomes focus on known toxic metals. Alternatively, this study assesses the extent to which exposure to a wider range of metals during gestation is associated with childhood morbidity. METHODS: We analyzed the concentrations of 25 metals found in urine samples of 111 pregnant women of Arab-Bedouin origin collected prior to birth. In addition, we collected medical records on their offspring for six years following birth, including every interaction with HMOs, local hospitals, and pharmacies. RESULTS: The main types of morbidities diagnosed and treated during this period were preterm births, malformations, asthma-like morbidity, cardiovascular and behavioral problems, and obesity. Multivariable analysis showed that offspring born before term were more likely to have been exposed to elevated maternal concentrations of zinc, thallium, aluminum, manganese, and uranium, all with adjusted relative risk above 1.40 for an increase by each quintile. Likewise, children with asthma had been exposed to higher levels of magnesium, strontium, and barium at gestation, while behavioral outcomes were associated with elevated biometals, i.e., sodium, magnesium, calcium, selenium, and zinc, as well as higher levels of lithium, cobalt, nickel, strontium, cadmium, vanadium, arsenic, and molybdenum. A heatmap of adjusted relative risk estimates indicates the considerable implications that exposure to metals may have for preterm birth and developmental outcomes. CONCLUSIONS The current study shows that perinatal exposure to metals is adversely associated with pediatric morbidity. Further such analyses on additional samples are warranted.
Adult ; Arabs/statistics & numerical data* ; Child ; Child, Preschool ; Environmental Pollutants/urine* ; Female ; Humans ; Israel ; Male ; Maternal Exposure/adverse effects* ; Metals/urine* ; Morbidity ; Pregnancy ; Prenatal Exposure Delayed Effects/epidemiology* ; Young Adult