National Children's Health Study

Patterns of illness among children in the United States and other industrially developed nations have changed substantially during the past 100 years. Before and during the first half of the previous century, infectious diseases were the primary threat to children's health. In contrast, the major illnesses and disorders that impair health, growth, and development today are chronic conditions stemming from the complex interaction of environmental exposures and inherent genetic factors. The Children's Health Act of 2000 directed the National Institute of Child Health and Development to conduct a national longitudinal study of environmental influences on children's health in the United States. The act specified that the study extend from the prenatal period to adulthood and investigate the short-term and long-term influences of physical, chemical, biological, and psychosocial environmental exposures on children's health and development, including behavioral, emotional, and educational outcomes in addition to physical health. The National Children's Study (NCS) is an observational longitudinal study that will enroll and follow a nationally representative sample of approximately 100,000 U.S.-born children from before birth through their 21st birthday. The study will screen all households within selected areas of 105 locations (primarily counties).

The major types of analysis of NCS data will include longitudinal exposure-outcome analysis, identification of causal pathways, analysis of neighborhood effects, evaluation of temporal effects within longitudinal data analysis of data from case-control data, and analysis of genomic data.

Women in their first trimester of pregnancy will be invited to participate in the pre-pregnancy portion of the NCS. Women who are not pregnant but have a high probability of becoming pregnant will be asked to participate in the early pregnancy portion of the NCS. All other eligible women will be asked if the study can contact them periodically to assess their pregnancy status. They also will be asked to contact the NCS should they become pregnant. Women identified as pregnant within 4 years after initial screening will be invited to enroll in the NCS.

The following information will be gathered:

Mother's data and information

• Questionnaire data-interviewed and self-administered (e.g., demographics; current pregnancy history; reproductive history; medical conditions; health behaviors; doctor visits; medicines and supplements; housing characteristics; pesticides, product use; occupation, hobbies; depression, stress; social support; diet; time and activity)
• Physical measures and clinical data (e.g., blood pressure, sonograms, height, weight, body measurements)
• Biologic specimens (e.g., blood, urine, hair, saliva)
• Environmental samples during home visits (e.g., dust, air, water)
• Medical record abstraction

Infant's data and information at birth

• Cord blood and tissue samples of the placenta and umbilical cord
• Standardized neurobehavioral exam
• Physical measures and clinical data (e.g., length; weight; circumferences of head, arm, abdomen, thigh)
• Meconium samples
• Medical diagnoses and treatment by report
• Selected Medical record abstraction

The National Children's Study (NCS) is a planned observational longitudinal Study that will enroll and follow a nationally representative sample of approximately 100,000 children born in the U.S to participating women from before birth through their 21st birthday. The goal of the NCS is to provide information that will ultimately lead to improvements in the health, development, and well-being of children. The primary aim of the NCS is to investigate the separate and combined effects of environmental exposures (chemical, biological, physical, and psychosocial) as well as gene-environment interactions on pregnancy outcomes, child health and development, and precursors of adult disease. In-person contacts with the NCS participants will include visits during pregnancy at the participant's home and in a clinical setting, collection of biologic samples and examination of the infant at birth, and periodic contacts with the family and child throughout infancy and childhood. Interim phone interviews between the in-person contacts also will occur. The NCS consists of the NCS Vanguard Study with any sub-studies and the NCS Main Study with any sub-studies. The Vanguard Study is the precursor to the Main Study.

The National Children's Study Vanguard Study is designed and implemented to determine the feasibility, acceptability and cost of the elements that will form the Main Study. The Vanguard Study is currently enrolling participants at seven Vanguard Centers and will have a planned duration of 21 years following completion of enrollment and will precede the Main Study on an ongoing basis to pilot all aspects of the Main Study. The specific objectives of the Vanguard Study are:

1. Evaluation of recruitment, enrollment and retention strategies
2. Evaluation of Study logistics and operations including sites and mechanisms of data acquisition, collection, transport and storage of environmental and biological samples and design and performance of information systems
3. Evaluation of Study visit assessments for feasibility, reliability, reproducibility, cost, value, redundancy with other assessments, stability and acceptability

Study visit assessments are the tests, environmental sample collections, biospecimens, questionnaires and other forms of data acquisition that are scheduled at the study visits.

The evaluation of the Vanguard Study will be based on a series of targeted and specific statistical techniques and tests selected for each evaluation. There will not be a single hypothesis to test. Instead multiple performance measures will be used to inform the scope, design, visit structure and schedule, mechanisms and procedures and analysis plan for the Main Study.

• Asthma
• Diabetes
• Obesity
• Premature Birth
• Autistic Disorder

• Ahlgren M, Melbye M, Wohlfahrt J, Sørensen TI. Growth patterns and the risk of breast cancer in women. N Engl J Med. 2004 Oct 14;351(16):1619-26.
• Akinbami L; Centers for Disease Control and Prevention National Center for Health Statistics. The state of childhood asthma, United States, 1980-2005. Adv Data. 2006 Dec 12;(381):1-24. No abstract available.
• Albalak R, McElroy RH, Noonan G, Buchanan S, Jones RL, Flanders WD, Gotway-Crawford C, Kim D, Dignam T, Daley WR, Jarrett J, Eduardo E, McGeehin MA. Blood lead levels and risk factors for lead poisoning among children in a Mexican smelting community. Arch Environ Health. 2003 Mar;58(3):172-83.
• Trasande L, Andrews HF, Goranson C, Li W, Barrow EC, Vanderbeek SB, McCrary B, Allen SB, Gallagher KD, Rundle A, Quinn J, Brenner B. Early experiences and predictors of recruitment success for the National Children's Study. Pediatrics. 2011 Feb;127(2):261-8. Epub 2011 Jan 24.

• IINCLUSION CRITERIA:
• Women aged 18-49 or pregnant residing in a selected NCS geographic segment at the time of enrollment
• Pregnancy women aged younger than 18, and residing in a selected NCS geographic segment at the time of enrollment, who are considered to be emancipated minors per the laws of their jurisdiction or minor pregnant women who obtain parental consent for participation
• Children born to enrolled women
• Biological fathers as identified by enrolled women
• Adult caregivers for enrolled children who have legal responsibility to authorize needed care for an enrolled child

EXCLUSION CRITERIA:

• For potentially eligible women: Womens' self-report of infertility
• Adults who are unable to understand what is involved in NCS participation and grant informed consent