National Children's Study Research Articles

Recommendations for Assessment of Environmental Exposures in Longitudinal Life Course Studies Such as the National Children's Study.

An important step toward understanding the relationship between the environment and child health and development is the comprehensive cataloging of external environmental factors that may modify health and development over the life course. Our understanding of the environmental influences on health is growing increasingly complex. Significant key questions exist as to what genes, environment, and life stage mean to defining normal variations and altered developmental trajectories throughout the life course and also across generations. With the rapid advances in genetic technology came large-scale genomic studies to search for the genetic etiology of complex diseases. While genome-wide association studies (GWAS) have revealed genetic factors and networks that advance our understanding to some extent, it is increasingly recognized that disease causation is largely non-genetic and reflects interactions between an individual's genetic susceptibility and his or her environment. Thus, the full promise of the human genome project to prevent or treat disease and promote good health arguably depends on a commitment to understanding the interactions between our environment and our genetic makeup and requires a design with prospective environmental data collection that considers critical windows of susceptibility that likely correspond to the expression of specific genes and gene pathways. Unlike the genome, which is static, relevant exposures as well as our response to exposures, change over time. This has fostered the complementary concept of the exposome ideally defined as the measure of all exposures of an individual over a lifetime and how those exposures relate to health. The exposome framework considers multiple external exposures (e.g., chemical, social) and behaviors that may modify exposures (e.g., diet), as well as consequences of environmental exposures indexed via biomarkers of physiological response or measures of behavioral response throughout the lifespan. The exposome concept can be applied in prospective developmental studies such as the National Children's Study (NCS) with the practical understanding that even a partial characterization will bring major advances to health. Lessons learned from the NCS provide an important opportunity to inform future studies that can leverage these evolving paradigms in elucidating the role of environment on health across the life course.

Accessibility Considerations in the National Children's Study.

In the National Children's Study (NCS), assessments were proposed and developed that used a wide range of modes of administration (e.g., direct in-person interviews, telephone interviews, computer assisted interviews, self-administered questionnaires, real time and recall observations, and physical examinations). These modes of administration may pose accessibility challenges for some people with disabilities. Accessibility of measurement is important to consider because systematic exclusion of people with disabilities from research can lead to measurement bias and systematic error in derived scores. We describe our approach to analyzing the accessibility of measures in the NCS and describe the work of the Accessibility Domain Team. Finally, we describe a decision process for creating and using accessible health research measures.

The National Children's Study Archive Model: A 3-Tier Framework for Dissemination of Data and Specimens for General Use and Secondary Analysis.

The National Children's Study (NCS) Archive was created as a repository of samples, data, and information from the NCS Vanguard Study—a longitudinal pregnancy and birth cohort evaluating approaches to study influence of environmental exposures on child health and development—to provide qualified researchers with access to NCS materials for use in secondary research. The National Children's Study Archive (NCSA) model is a 3-tiered access model designed to make the wealth of information and materials gathered during the NCS Vanguard Study available at a user appropriate level. The NCSA model was developed as a 3-tier framework, for users of varying access levels, providing intuitive data exploration and visualization tools, an end-to-end data and sample request management system, and a restricted portal for participant-level data access with a team of experts available to assist users. This platform provides a model to accelerate transformation of information and materials from existing studies into new scientific discoveries.Trial Registration: ClinicalTrials.gov Identifier: NCT00852904 (first posted February 27, 2009).

Prenatal exposure to multiple metals and birth outcomes: An observational study within the National Children's Study cohort

BackgroundPrenatal exposure to metals may play an important role in fetal growth. However, the epidemiologic evidence for certain metals is sparse, and most of the existing research has focused on evaluating single metals in highly exposed target populations. ObjectivesWe evaluated associations of cadmium, lead, manganese, selenium, and total mercury exposures during pregnancy with fetal growth using data from mother-infant pairs participating in the National Children's Study. MethodsPrenatal metal exposures were measured using maternal blood collected from 6 to 32 weeks of gestation. Birth outcomes, including gestational age, birthweight, birth length, head circumference, and ponderal index, were ascertained through physical measurement at birth or abstraction from medical records. Regression coefficients and their 95% confidence intervals were estimated from multivariable linear regression models in the overall study population as well as among male and female infants. We further evaluated pairwise metal–metal interactions. ResultsSex-specific associations were observed for lead, with inverse associations for birthweight, birth length, head circumference, and gestational age observed only among female infants. Sex-specific associations were also observed for selenium, with a positive association for birthweight observed among male infants; selenium was also positively associated with ponderal index and inversely associated with birth length among female infants. Overall, total mercury was inversely associated with birthweight and ponderal index, and the association with birthweight was stronger among female infants. No significant associations were observed with cadmium and manganese. In the metal–metal interaction analyses, we found evidence of a synergistic interaction between lead and total mercury and antagonistic interaction between selenium and total mercury with selected birth outcomes. ConclusionsOur findings suggest that prenatal exposure to metals may be related to birth outcomes, and infant sex may modify these associations.

Managing Chronic Health Needs in Child Care and Schools—Food Allergies

Patient Education| 2021 Managing Chronic Health Needs in Child Care and Schools—Food Allergies Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Facebook Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Managing Chronic Health Needs in Child Care and Schools—Food Allergies. Pediatric Patient Education 2021; 10.1542/ppe_document120 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search nav search search input Search input auto suggest search filter All AAP SitesAll PublicationsPediatric Patient Education Search Advanced Search Subjects: Managing Chronic Health Needs in Child Care Allergy is the term used to describe the body’s overreaction to something that it views as foreign or different from itself. The body reacts by releasing histamine and other substances that cause allergic symptoms. The things that people are allergic to are called allergens.There are many different types of allergic reactions; some are minor and annoying, but some are serious and life-threatening.One form of a serious allergic reaction is called anaphylaxis (see Anaphylaxis Quick Reference Sheet). Food is a common trigger of anaphylaxis.Foods that most commonly cause allergies includePeanutsTree nutsSoyMilkWheatEggsFish and shellfish Allergies are very common. In a national study of children with special health care needs, 53% of them had allergies of some type. Children with food allergies may or may not have other allergic conditions such as eczema (atopic... © 2019 American Academy of Pediatrics. All rights reserved. You do not currently have access to this content.

Third trimester maternal vitamin D and early childhood socioemotional development.

Whether maternal vitamin D affects offspring socioemotional development in early childhood has been underexplored. This study examined associations between maternal vitamin D during in the 3rd trimester and offspring socioemotional development between 30 and 59months. Data from 87 maternal-offspring pairs enrolled in the National Children's Study were used. Total plasma maternal vitamin D (25-hydroxyergocalciferol+25-hydroxycholecalciferol) was measured between 28 and 35 gestational weeks and categorised as quartiles (Q). Multivariable regression models, adjusting for maternal race/ethnicity, education, and prepregnancy body mass index (BMI [kg/m2 ]), were used to estimate the association between vitamin D and offspring scores on the Brief Infant-Toddler Social and Emotional Assessment (BITSEA). The mean (standard deviation) vitamin D concentration was 86.5 (27.8) nmol/L. The median (range) BITSEA problem score was 6.0 (0.0-30.0), and competence score was 19.0 (7.0-22.0). Maternal vitamin D was inversely related to offspring problem scores. Compared to offspring of women with 25(OH)D in Q1, offspring problem scores were -4.80 (95% confidence interval [CI] -8.29, -1.33) units lower for Q2 vs Q1, -5.64 (95% CI -9.60, -1.68) units lower for Q3 vs Q1, and -4.70 (95% CI -8.59, -0.82) units lower for Q4 vs Q1. Vitamin D was not associated with offspring competence score. Higher maternal vitamin D was associated with lower offspring behaviour problems and not associated with socioemotional competence. These data indicate the association of maternal vitamin D and offspring development may be dependent on the specific developmental component being investigated.

Maternal H-antigen secretor status is an early biomarker for potential preterm delivery.

Pre-pregnancy or first trimester biomarkers predicting preterm delivery are lacking. The purpose of this study was to determine whether maternal H-antigen (secretor status) is a potential biomarker for preterm delivery. This cohort study examined maternal saliva samples and birth data gathered by the National Children's Study Vanguard pilot phase (2009-2014) and included 300 women who were ≥18 years old and provided birth data and saliva samples. The maternal secretor status phenotype was determined by quantifying H-antigen in saliva using enzyme-linked immunoassay. Mothers were stratified by secretor status and multivariable analysis estimated adjusted associations with preterm delivery. Maternal lack of H-antigen production was an independent risk factor for preterm delivery after adjusting for known confounders (aOR 4.53; 95% CI: 1.74, 11.81; P = 0.002). Maternal H-antigen may be a biomarker identifying women at-risk for preterm delivery. Prospective cohort studies validating these findings are needed.

PFAS concentration during pregnancy in relation to cardiometabolic health and birth outcomes

IntroductionPoly- and perfluoroalkyl substances (PFAS) are persistent organic pollutants with pervasive exposure and suspected associations with metabolic abnormalities and adverse pregnancy outcomes. The goal of the present study was to examine the relationship between serum-PFAS concentrations measured in late pregnancy with relevant outcomes. MethodsThe study sample included 433 pregnant women enrolled in the Vanguard Pilot Study of the National Children's Study. Six PFAS were measured in primarily third trimester serum, as well as fasting insulin, total cholesterol, and triglycerides. The PFAS were examined in quartiles in relation to serum biomarkers, gestational age at birth and birth weight standardized for gestational age using multivariable-adjusted regression models. ResultsOver 98% of the study population had detectable concentrations of four of the PFAS, and concentrations varied by race/ethnicity. Total cholesterol was positively associated with PFDA, PFNA, and PFOS, and triglycerides with PFDA, PFNA, PFOS, and PFOA, but PFAS were not associated with fasting insulin in adjusted models. Only PFNA was associated with an increased odds of birth at <37 weeks gestation. PFAS were generally not associated with birth weight, though PFHxS was associated with the first quartile of birth weight among males only. ConclusionsThis study of pregnant U.S. women supports the ubiquitous exposure to PFAS and positive associations between PFAS exposure with serum-lipid concentrations. PFAS were largely unassociated with gestational age at birth and birth weight, though PFNA was associated with preterm birth. The results support the vulnerability to PFAS exposure of pregnancy.

Food insecurity, gestational weight gain and gestational diabetes in the National Children's Study, 2009-2014.

Household food insecurity (HFI) and gestational diabetes mellitus (GDM) are both common during pregnancy, yet it is unknown if these two factors are related. We aimed to determine the independent and joint associations between HFI, gestational weight gain (GWG) and GDM among pregnant women in the USA. We used data from 592 women in the National Children's Study, Initial Vanguard Study from 2009 to 2014. HFI was assessed using the Household Food Security Survey Module at the first study visit; GDM was assessed through questionnaires and medical chart review. Logistic regression models were used to investigate the exposures of HFI, GWG and their joint effect on GDM. Among participants, 20.1% were marginally food secure or food insecure and 7.4% were diagnosed with GDM. The elevated unadjusted association between HFI and GDM was attenuated after adjustment (aOR: 1.12; 95%CI: 0.47, 2.66). There was an elevated risk of GDM associated with inadequate GWG, (aOR: 2.42; 95%CI: 0.97, 6.00), but results were imprecise. There were no statistically significant associations in the joint exposure analysis. The relationship between HFI and GDM is mostly explained by other covariates, but there is some evidence that inadequate GWG is a possible risk factor for GDM.

Household food insecurity and antepartum depression in the National Children's Study

PurposeThe purpose of this study was to determine the association between household food insecurity (HFI) and elevated antepartum depressive symptoms (EADS) in the National Children's Study, 2009–2014, as well as standardize our results to the U.S. pregnant population. MethodsHFI was collected at participants’ baseline visits using the U.S. Household Food Security Survey Module; antepartum depression symptoms were collected twice during pregnancy using the Center for Epidemiologic Study Depression scale. Generalized estimating equations for binary outcomes were used to estimate the association between HFI and EADS. Inverse probability weighting was used to generalize the effect to the U.S. population using the National Health and Nutrition Examination Survey. ResultsAmong 746 participants, 20.6% were food insecure. Women who were food insecure were 3.39 times (95% confidence interval: 1.73, 6.62) as likely to report EADS compared with women who were food secure. This estimate was marginally strengthened in a weighted analysis (odds ratio: 3.68; 95% confidence interval: 1.43, 9.43). ConclusionsThis study suggests that women who are food insecure are at a greater risk of EADS, and HFI should be evaluated when assessing antepartum depression.

Association between prenatal arsenic exposure, birth outcomes, and pregnancy complications: An observational study within the National Children's Study cohort

BackgroundChronic arsenic exposure has been associated with pregnancy complications and reduced fetal growth in populations where total arsenic exposure exceeds 50 μg/L. However, the potential effect on pregnancy outcomes remains unclear at lower levels of arsenic exposure, such as those most commonly observed in the United States. ObjectivesWe evaluated the associations between arsenic exposure during pregnancy with fetal growth and risk of pregnancy complications using data from mother-infant pairs participating in the National Children's Study. MethodsPrenatal arsenic exposure was measured using maternal urine collected during the third trimester. Information about pregnancy complications was abstracted from medical records. Fetal growth, including gestational age, birth weight, birth length, head circumference, and ponderal index, was ascertained through physical measurement at birth and extracted from medical records. ResultsMedians [interquartile range (IQR)] of maternal urinary total arsenic and dimethylarsinic acid (DMA) were 7.77 μg/L (7.98) and 3.44 μg/L (3.13), respectively. Each increase in IQR of prenatal total arsenic level was associated with greater birth length (+0.28 cm; 95% CI: 0.14, 0.42), greater head circumference (+0.12 cm; 95% CI: 0.04, 0.21), and lower ponderal index (−0.37 kg/m3; 95% CI: −0.58, −0.17). Similar results were obtained for levels of prenatal DMA. Tests for multiplicative interaction indicate that prenatal urinary DMA was negatively associated with gestational age among female infants (−0.44 week decrease in gestational age estimated for each IQR increase in DMA; 95% CI: −0.84, −0.05), while no association was observed among male infants (pinteraction = 0.02). No significant associations were detected between arsenic and birth weight or pregnancy complications. ConclusionsHigher prenatal arsenic exposure was associated with longer birth length, greater head circumference, and lower ponderal index. Associations between arsenic and gestational age may be modified by infant sex.

Screening for Pregnancy Status in a Population-Based Sample: Characteristics Associated with Item Nonresponse.

Population-based recruitment of a cohort of women who are currently pregnant or who may become pregnant in a given timeframe presents challenges unique to identifying pregnancy status or the likelihood of future pregnancy. Little is known about the performance of individual eligibility items on pregnancy screeners although they are critical to participant recruitment. This paper examined the patterns and respondent characteristics of key pregnancy screener items used in a large national study. Cross-sectional analyses were conducted. Descriptive statistics and multivariable logistic regression models were used to examine nonresponse patterns to three questions (currently pregnant, trying to get pregnant and able to get pregnant). The questions were asked of 50,529 women in 17 locations across the US, as part of eligibility screening for the National Children's Study Vanguard Study household-based recruitment. Most respondents were willing to provide information about current pregnancy, trying, and able to get pregnant: 99.3% of respondents answered all three questions and 97.4% provided meaningful answers. Nonresponse ranged from 0.3 to 2.5% for individual items. Multivariable logistic regression results identified small but statistically significant differences in nonresponse by respondent age, marital status, race/ethnicity-language, and household-based recruitment group. The high levels of response to pregnancy-related items are impressive considering that the eligibility questions were fairly sensitive, were administered at households, and were not part of a respondent-initiated encounter.

Placental gross shape differences in a high autism risk cohort and the general population.

A growing body of evidence suggests that prenatal environment is important in Autism Spectrum Disorder (ASD) etiology. In this study, we compare placental shape features in younger siblings of children with ASD, who themselves are at high ASD risk, to a sample of low risk peers. Digital photographs of the fetal placenta surface and of the sliced placental disk from 129 high ASD risk newborns and from 267 newborns in the National Children’s Study Vanguard pilot were analysed to extract comparable measures of placental chorionic surface shape, umbilical cord displacement and disk thickness. Placental thickness measures were moderately higher in siblings of ASD cases. The placentas of ASD-case siblings were also rounder and more regular in perimeter than general population placentas. After stratification by sex, these across-group differences persisted for both sexes but were more pronounced in females. No significant differences were observed in cord insertion measures. Variations in placental shape features are generally considered to reflect flexibility in placental growth in response to changes in intrauterine environment as the placenta establishes and matures. Reduced placental shape variability observed in high ASD risk siblings compared to low-risk controls may indicate restricted ability to compensate for intrauterine changes.

Prior Trauma Exposure and Serious Illness at End of Life: A National Study of Children in the U.S. Foster Care System From 2005 to 2015

ContextChildren in foster care suffer with serious illness at end of life. However, the relationship between prior trauma exposure and serious illness has received little empirical attention. ObjectivesThe objectives were to examine the prevalence and type of trauma exposure and investigate the relationship between prior trauma and serious illness among foster children at end of life. MethodsWe used national longitudinal foster care data. We included children who were younger than 18 years with residence in the U.S. Serious illness (i.e., physical health, mental/behavioral health, developmental disabilities) was measured via the foster care files. Three measures of prior trauma exposure (i.e., maltreatment, drug/alcohol exposure, psychosocial stressors) were created. Using multivariate logistic regressions, we evaluated the influence of prior trauma on serious illness at end of life, while controlling for demographic, geographic, and foster care support characteristics. ResultsSixty-eight percent of children experienced maltreatment, 28% exposure to parental drug/alcohol misuse, and 39% psychosocial stressors before entering foster care. Maltreatment was positively associated with physical health and developmental disabilities, whereas parental drug/alcohol exposure was inversely related to developmental disabilities. Psychosocial stressors contributed to the prediction of poor physical, mental, and developmental health. ConclusionThese findings suggest that trauma-informed end-of-life care may be a critical need among children in foster care with serious illness. Future directions are discussed, including collaboration between end-of-life clinicians and social service workers and the importance of future research to understand and improve the quality of health at end of life for this underserved population.

Breastfeeding Trends Among Very Low Birth Weight, Low Birth Weight, and Normal Birth Weight Infants

To examine the change in breastfeeding behaviors over time, among low birth weight (LBW), very low birth weight (VLBW), and normal birth weight (NBW) infants using nationally representative US data. Univariate statistics and bivariate logistic models were examined using the Early Child Longitudinal Study-Birth Cohort (2001) and National Study of Children's Health (2007 and 2011/2012). Breastfeeding behaviors improved for infants of all birth weights from 2007 to 2011/2012. In 2011/2012, a higher percentage of VLBW infants were ever breastfed compared with LBW and NBW infants. In 2011/2012, LBW infants had a 28% lower odds (95% CI, 0.57-0.92) of ever breastfeeding and a 52% lower odds (95% CI, 0.38-0.61) of breastfeeding for ≥6 months compared with NBW infants. Among black infants, a larger percentage of VLBW infants were breastfed for ≥6 months (26.2%) compared with LBW infants (14.9%). Breastfeeding rates for VLBW and NBW infants have improved over time. Both VLBW and NBW infants are close to meeting the Healthy People 2020 ever breastfeeding goal of 81.9%. LBW infants are farther from this goal than VLBW infants. The results suggest a need for policies that encourage breastfeeding specifically among LBW infants.

Analysis of demographic differences in intent to breastfeed and sustained breastfeeding in The National Children's Study

Purpose: To demonstrate the utility of The National Children's Study (NCS) data for pediatrics research. Methods: Perform statistical analyses of demographic differences in breastfeeding intent and sustained breastfeeding utilizing NCS data. Results: The National Children’s Study (NCS), a prospective study of children and mothers covering the prenatal, perinatal, and postnatal stages up to age 5, provides to researchers a wealth of data pertaining to many areas of child and maternal health, including breastfeeding. Several publications document demographic differences in sustained breastfeeding rates. NCS data are consistent with …

Analysis of demographic differences in intent to breastfeed and sustained breastfeeding in The National Children's Study

Analysis of demographic differences in intent to breastfeed and sustained breastfeeding in The National Children's Study

The relationship among school safety, school satisfaction, and students' cigarette smoking: Based on a multilevel mediation model

BackgroundSchool context greatly affects students' cigarette smoking. Based on the ‘context–process–outcomes’ model, this study investigated school safety as a context variable to explore how safety (at the school level) affects students' smoking behaviours. MethodsHierarchical linear modelling was used to examine the link between school safety at the school level and students' cigarette smoking, with school satisfaction as a mediator. Data were obtained from the National Children's Study of China (2009), where 24,013 fourth- to ninth-grade students from 607 schools were recruited from 100 counties in 31 provinces (boys 52.9%, elementary school students 50.1%, middle school students 49.9%). ResultsStudent-level and school-level factors were associated with an increased likelihood of cigarette smoking. Multilevel mediation analyses showed that school safety problems increased the behaviour of cigarette smoking directly as well as indirectly through student's school satisfaction, controlling for both student- and school-level covariates; its direct effect was larger than its indirect effect. A gender difference also existed in the multilevel mediation model: for girls, school satisfaction fully mediated the relationship between school safety at the school level and cigarette smoking, but only partially for boys. There was no grade-stage difference in the multilevel mediation model. ConclusionsLimitations of the study as well as implications are discussed. School safety should receive increased attention from policymakers because of its impact on students' cigarette smoking behaviour. The construction of a safe school climate should be approached dynamically and multi-perspectivally.

Introduction and Goals for the National Children's Study.

The National Children’s Study (NCS) evolved in concept and planning to become an integrated systems based initiative to assess a full spectrum of health and capture the environmental factors and other influences that shape the trajectory of child development. The NCS built on prior work in health assessment, epidemiology, logistics, and methodology in order to address the broad goals of its mandate. To develop the specific methods and tools to conduct a study in multiple environments outside conventional health care delivery clinics the NCS invested in new approaches such as informatics, study operations, and the establishment of a Health Measurements Network to provide accurate, cost effective, and scientifically valid data that would be interoperable with data collected by other longitudinal studies around the world as well as with major national and international health improvement initiatives.

Dried Blood Spot Reference Intervals for Steroids and Amino Acids in a Neonatal Cohort of the National Children's Study.

Reference intervals from children are limited by access to healthy children and their limited blood volumes. In this study we set out to fill gaps in pediatric reference intervals for amino acids and steroid hormones using dried blood spots (DBS) from a cohort of the National Children's Study. Deidentified DBS annotated with age, birthweight, sex, and geographic location were obtained from 310 newborns aged 0-4 days and analyzed for 25 amino acids and 4 steroid hormones using LC-MS/MS. Nonparametric statistical approaches were used to generate the 2.5th-97.5th percentile distributions for newborns. Paired plasma/DBS specimens were used to mathematically transform DBS reference intervals to corresponding plasma intervals. 10 of 25 DBS amino acid distributions were dependent on sex. There was little correlation with age, birthweight, or geographic location over the first 4 days of life. In most cases, transformation of DBS distributions to plasma distributions faithfully reflected independent studies of newborn plasma amino acid distributions. In general newborn steroid distributions were negatively correlated with age and birthweight over the first 4 days of life. Data distributions for the 4 steroids were not found related to geographic location, but testosterone concentrations displayed sex dependence. Transformation of DBS distributions to plasma intervals did not faithfully replicate other neonate steroid reference intervals determined directly with plasma. These data demonstrate the feasibility and utility of deriving newborn reference intervals from large numbers of archived DBS samples such as those obtained from the National Children's Study biobank.