National Children's Study Research Articles

The Future of the National Children's Study.

The Future of the National Children's Study.

In the Aftermath of the National Children's Study.

In the Aftermath of the National Children's Study.

Exploring the associations between microRNA expression profiles and environmental pollutants in human placenta from the National Children's Study (NCS)

Exploring the associations between microRNA expression profiles and environmental pollutants in human placenta from the National Children's Study (NCS)

Use of multi-modal community outreach and media to support recruitment in the National Children's Study

ObjectiveThe National Children's Study (NCS) is a prospective, national longitudinal study of the effects of environment and genetics on child health, growth, and development. The objective of this study is to describe and evaluate the Maine Study Center's community outreach effort, describing the rationale for its design, evolving implementation, and to evaluate the overall campaigns’ effectiveness on recruitment as reported by potential participants.MethodsWe evaluated the outreach and media campaign using conventional media metrics, demographic characteristics, how women self reported hearing about the study, and response rates between those who refused participation in the study, and those who consented. Data were collected from December 2010 through August 2011.ResultsSeventy-three percent of women who consented reported having heard of the NCS previously, in contrast to just over half of women who refused to participate or were ineligible women. Women who consented reported modalities slightly more frequently than those who refused participation.The findings suggest that outreach and media can be effective in supporting recruitment in population-based studies; however, additional research is needed to evaluate these strategies and standardize metrics.

The National Children's Study 2014: Commentary on a Recent National Research Council/Institute of Medicine Report

The National Children's Study 2014: Commentary on a Recent National Research Council/Institute of Medicine Report

Transitions in Intention to Become Pregnant in Women Enrolled in the National Children’s Study Initial Vanguard Study

Transitions in Intention to Become Pregnant in Women Enrolled in the National Children’s Study Initial Vanguard StudyAbstract Number:1965 Dean Baker*, Joseph Stanford, Tiandong Li, Richard Hamman, Jennifer Kwan, and Ulrike Luderer Dean Baker* Center for Occupational and Environmental Health, University of California, Irvine, United States, E-mail Address: [email protected] Search for more papers by this author , Joseph Stanford Department of Family and Preventive Medicine, University of Utah, United States, E-mail Address: [email protected] Search for more papers by this author , Tiandong Li Westat, United States, E-mail Address: [email protected] Search for more papers by this author , Richard Hamman Department of Epidemiology, Colorado School of Public Health, United States, E-mail Address: [email protected] Search for more papers by this author , Jennifer Kwan National Children's Study, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States, E-mail Address: [email protected] Search for more papers by this author , and Ulrike Luderer Center for Occupational and Environmental Health, University of California, Irvine, United States, E-mail Address: [email protected] Search for more papers by this author AbstractBACKGROUND. Prospective studies of the effects of the preconception environment on children’s health necessitate recruiting women prior to conception. The National Children’s Study (NCS) is a large United States (US) birth cohort study, which provided an opportunity to assess changes in pregnancy intention in a large sample of US women and evaluate the feasibility of preconception enrollment.METHODS. The initial NCS design was a multi-stage cluster sample of 105 locations. The NCS selected seven locations to pilot test household-based enumeration and recruitment methods. Women were screened for pregnancy and, if not pregnant, for the likelihood of future pregnancy. An algorithm was used to assign low, moderate, or high probability of pregnancy (PPG) based on sexual activity and use of contraception. High PPG women were considered ‘tryers’ if they were planning to conceive. Follow-up of non-pregnant women was by periodic telephone calls. Logistic regression was used to examine initial PPG status by demographic characteristics. A proportional hazards model is being developed to model rates of PPG status transitions.RESULTS. The study screened 20,350 women who were eligible for pre-pregnancy follow-up and completed follow-up contact on 64%. The distribution of PPG status at first contact was Low (58%); Moderate (30%); High Non-Tryer (8.3%), and High Tryer (3.4%). Women initially in the high PPG groups were more likely to be age 25-30 years, married, and Black or Hispanic. Follow-up rates were higher among younger, married, White women. The crude rate of becoming pregnant as the first PPG status transition varied dramatically by initial PPG status: Low (0.2); Moderate (0.6); High Non-Tryer (1.7); and High Tryer (6.5) per 100 person-months. DISCUSSION. Focusing on women who are trying to become pregnant can be an efficient recruitment strategy to study preconception exposures. However, such a strategy may be biased because these women differ from other women.

In Vitro Study of Bisphenol A (BPA) in the early human placenta

In Vitro Study of Bisphenol A (BPA) in the early human placenta

Central placenta processing to optimize multicenter collection, analysis, and storage of human placental tissue in the National Children’s Study (NCS)

Central placenta processing to optimize multicenter collection, analysis, and storage of human placental tissue in the National Children’s Study (NCS)

Human placental study of genetics/genomic, environmental contaminant and morphology assessments from 12 U.S. Counties – Methods and results from the U.S. National Children’s Study (NCS)

Human placental study of genetics/genomic, environmental contaminant and morphology assessments from 12 U.S. Counties – Methods and results from the U.S. National Children’s Study (NCS)

Quantitative analysis of bisphenol a in human placentae from nine counties across the U.S.: National Children’s Study (NCS)

Quantitative analysis of bisphenol a in human placentae from nine counties across the U.S.: National Children’s Study (NCS)

Exploring the biometal composition of human placentae from the U.S. National Children's Study (NCS)

Exploring the biometal composition of human placentae from the U.S. National Children's Study (NCS)

Validation of drinking water disinfection by-product exposure assessment for rural areas in the National Children's Study.

The objective of this study was to provide evidence to evaluate the proposed National Children's Study (NCS) protocol for household water sampling in rural study areas. Day-to-day variability in total trihalomethane (TTHM) concentrations in community water supplies (CWS) in rural areas was determined, and the correlation between TTHM concentrations from household taps and CWS monitoring reports was evaluated. Daily water samples were collected from 7 households serviced by 7 different CWS for 15 days. Coefficients of variation for TTHM concentration over 15 days ranged from 8% to 20% depending on the household. Correlations were tested between TTHM household concentrations and the closest date- and location-matched CWS monitoring reports for the 15-day mean (R=0.85, P<0.01). To simulate the NCS-proposed protocol, correlations were tested for 30 additional NCS household samples (polynomial fit: R=0.74, P=0.04). CWS reported TTHM concentrations >50 μg/l corresponded to measured NCS household concentrations ranging from 2 to 60 μg/l. TTHM concentrations were higher in CWS than NCS samples (11.2±3.2 μg/l, mean difference±SE, P<0.01). These results show that in rural areas there is high variability within households and poor correlation at higher concentrations, suggesting that TTHM concentrations from CWS monitoring reports are not an accurate measure of exposure in the household.

Recruitment of women in the National Children's Study Initial Vanguard Study.

The initial Vanguard Study of the National Children's Study was conducted during 2009-2010 in 7 locations in the United States. A goal was to evaluate the feasibility and yield of a household-based sampling design to recruit pregnant women. A multistage area probability sampling design was used to identify study locations (generally, counties) that were subsequently divided into smaller geographical units, termed segments. Between 7 and 18 segments were selected in each location, and dwelling units within segments were listed. A household-based recruitment process was implemented, which included enumeration of households to identify age-eligible women, pregnancy screening to identify pregnant women eligible for immediate enrollment and nonpregnant women for telephone follow-up, and administration of informed consent to eligible women. After a recruitment period of 17-20 months, 67,181 (89%) households were enumerated, which identified 34,172 (88%) age-eligible women to whom the pregnancy screener was administered. Among those who completed the screener, 2,285 women became eligible for enrollment, of whom 1,399 (61%) enrolled. Although response rates were fairly high at initial contact and among pregnant women, the overall yield was lower than anticipated. In particular, telephone follow-up of nonpregnant women was not a practicable strategy for prospective recruitment of newly pregnant women.

Results of whole-genome analysis from National Children's Study (NCS)

Results of whole-genome analysis from National Children's Study (NCS)

Environmental exposures during pregnancy: US National Children's Study formative research investigation

omics data sets with measured environmental contaminants and pregnancy outcome data. Study Design: As part of the NCSMain Study, 210 placentas from 10 regional centers were uniformly collected and stored with a priori protocols designed to preserve biologic material for future 'omics research. Subsequent DNA/RNA/miRNA/methylated DNA analysis, analytic chemistry for environmental exposures, and 3-D placental imaging and mapping were conducted by established experts from over 20 collaborating centers. High dimensional data sets were reduced and integrative analysis to determine the interrelationships among biologic measures was undertaken. RNA levels for all annotated transcripts (UCSC & Ensembl) were normalized to construct a weighted coexpression gene network. Leveraged variant information derived from placental RNA sequencing enabled construction of a weighted gene network of 20,000 most variable gene expression traits. 1 million SNPs and SNPs from 1000 genomes (14 million SNP genotypes per sample) were imputed across all samples, and placental eQTL were mapped to identify enriched loci at p b 0.00001. Results: A heretofore unparalleled data set was generated and analyzed to yield novel placental interaction networks (Figure). The placental co-expression network indicates strong structurally segregated regions of the placental molecular interactome, generating 20 modules, each containing between 30 and 4000 gene members. In testing for pathway enrichments across all modules, we uncovered not only thousands of loci modulating the expression of genes in the placenta, but one subnetwork (yellow nodes/red edges) that was enriched for pathways, SNPs, and toxins previously associated with autism and associated spectrumdisorders. Conclusion:Wedemonstrate for the first time that population-derived high dimensional placental multi'omics data can be integrated with systems biology approaches. These comprehensive molecular profiles,when taken in the context of other high-dimensional phenotypic data, promise to enhance our understanding of a variety of biological processes that are modulated in the placenta and in turn associate with later human disease.

Streamlining the diagnosis of autism spectrum disorder for the National Children's Study

Streamlining the diagnosis of autism spectrum disorder for the National Children's Study

An integrated framework for linking exposure and phenotypic data in the National Children's Study

An integrated framework for linking exposure and phenotypic data in the National Children's Study

Novel insights on the molecular targets of environmental exposures during pregnancy using placental multi'omics data integration in the National Children's Study (NCS)

Novel insights on the molecular targets of environmental exposures during pregnancy using placental multi'omics data integration in the National Children's Study (NCS)

Smoking and its risk factors in Chinese elementary and middle school students: A nationally representative sample study

ObjectiveThe purpose of this study was to examine the prevalence of smoking in a nationally representative sample of Chinese elementary and middle school students and to investigate its risk factors from families and schools. MethodThe data were from the National Children's Study of China (NCSC), in which 24,013 fourth- to ninth-grade students were recruited from 100 counties in 31 provinces in China. Chi-square tests and one-way ANOVAs were used to analyze the relationships between smoking and the risk factors. Logistic regressions were used to calculate odds ratios. ResultsThe prevalence of ever smokers and current smokers were 19.0% and 5.4%. Focusing on current smokers, boys, middle school students, rural students, boarding students, non-only children and those owning parents with low educational levels reported smoking significantly more than girls, elementary school students, urban students, non-boarding students, only children and those owning parents with high educational levels. Lower trust and support from teachers and higher parent–child conflict positively predicted both smoking and smoking frequency. Lower trust and support from classmates was associated with higher possibility of smoking. However, higher trust and support from classmates was associated with higher smoking frequency. Teacher smoking and friend smoking were only predictive of smoking, but not of smoking frequency. ConclusionsBoys, middle school students, rural students, boarding students, non-only children and those owning parents with low educational levels need special attention. The most risk factors for smoking and smoking frequency were lower trust and support from teachers and higher parent–child conflict.

A Tiered Framework for Risk‐Relevant Characterization and Ranking of Chemical Exposures: Applications to the National Children's Study (NCS)

A challenge for large-scale environmental health investigations such as the National Children's Study (NCS), is characterizing exposures to multiple, co-occurring chemical agents with varying spatiotemporal concentrations and consequences modulated by biochemical, physiological, behavioral, socioeconomic, and environmental factors. Such investigations can benefit from systematic retrieval, analysis, and integration of diverse extant information on both contaminant patterns and exposure-relevant factors. This requires development, evaluation, and deployment of informatics methods that support flexible access and analysis of multiattribute data across multiple spatiotemporal scales. A new "Tiered Exposure Ranking" (TiER) framework, developed to support various aspects of risk-relevant exposure characterization, is described here, with examples demonstrating its application to the NCS. TiER utilizes advances in informatics computational methods, extant database content and availability, and integrative environmental/exposure/biological modeling to support both "discovery-driven" and "hypothesis-driven" analyses. "Tier 1" applications focus on "exposomic" pattern recognition for extracting information from multidimensional data sets, whereas second and higher tier applications utilize mechanistic models to develop risk-relevant exposure metrics for populations and individuals. In this article, "tier 1" applications of TiER explore identification of potentially causative associations among risk factors, for prioritizing further studies, by considering publicly available demographic/socioeconomic, behavioral, and environmental data in relation to two health endpoints (preterm birth and low birth weight). A "tier 2" application develops estimates of pollutant mixture inhalation exposure indices for NCS counties, formulated to support risk characterization for these endpoints. Applications of TiER demonstrate the feasibility of developing risk-relevant exposure characterizations for pollutants using extant environmental and demographic/socioeconomic data.