NATIONAL CHILDREN'S STUDY

国家儿童研究（NCS）是一项前瞻性纵向队列研究，研究环境暴露和基因环境相互作用对儿童健康和发育的个体和综合影响，研究对象是在美国出生的约10万名儿童的代表性样本。这些孩子将从出生前一直被跟踪到21岁。这项研究的重要性和及时性基于许多因素，包括过去的经验表明，环境暴露（如怀孕期间接触酒精和幼儿期接触铅）对儿童健康和发育的深远影响；与成人相比，儿童对环境暴露的特殊脆弱性；已知的持续接触，如非持久性农药的普遍水平或幼儿每天接触媒体的时间；以及环境对自闭症、发育迟缓和发育障碍、哮喘和肥胖等高影响疾病的影响或原因的证据。全国健康调查的主要目的是调查环境暴露（化学、生物、物理、社会心理）以及基因-环境相互作用对妊娠结局、儿童健康和发育以及成人疾病前兆的单独和综合影响。这项研究的独特之处在于，它关注的是怀孕初期（以及之后）的环境暴露，以及计划暴露的广度和结果测量。NCS响应2000年儿童健康法案的国会授权，即NICHD和一个联邦机构联盟计划并开展一项关于环境暴露对儿童影响的纵向研究。

The National Children's Study (NCS) is prospective longitudinal cohort study of the individual and combined effects of environmental exposures and gene environmental interactions on child health and development in a representative sample of approximately 100,000 children born in the United States. The children will be followed from before birth until age 21. The importance and timeliness of this study are based on many factors, including past experiences demonstrating profound effects of environmental exposures, such as exposures to alcohol during pregnancy and to lead in early childhood on child health and development; the special vulnerabilities of children to environmental exposures compared to adults; known ongoing exposures, such as prevalent levels of non-persistent pesticides or hours of media exposure per day in young children; and evidence for environmental contributions or causes to such high-impact conditions as autism, developmental delay and developmental disability, asthma, and obesity. The primary aim of the NCS is to investigate the separate and combined effects of environmental exposures (chemical, biological, physical, psychosocial) as well as gene-environment interactions on pregnancy outcomes, child health and development, and precursors of adult disease. Unique features of the study include its focus on environmental exposures at the earliest stages of pregnancy (as well as thereafter) and the breadth of planned exposure and outcome measurements. The NCS responds to the Congressional mandate of the Children's Health Act of 2000, that the NICHD and a consortium of federal agencies plan and conduct a longitudinal study of the impacts of environmental exposures on children. The NCS will employ a national probability sampling approach to select locations and participants for conduct of the study. The sampling design utilizes a multistage clustered approach. In the first stage, 105 locations (generally corresponding to single counties) were randomly selected from all U.S. counties. Seven of the locations serve as the initial or Vanguard Locations, participating in the pilot phase of the NCS. Because the focus of the study includes assessment of the impact of exposures that occur early in pregnancy, both pregnant women and their partners, and women of childbearing age, comprise the initial target population for enrollment. Data will be collected in combinations of face-to-face contacts and remote collection methods, e.g., telephone, computer, or mail-in questionnaires. The expected frequency of contact (face-to-face or remote) is approximately every three months through age one, every six months through age five years and annually thereafter. For a sample of children enrolled in the study, visits will also be made to child care and school settings for collection of environmental samples and observational data. Anticipated biologic specimens include blood, urine, hair, and nail clippings from mothers and children; blood, urine, and hair from fathers; cord blood, umbilical cord and placental tissues, and meconium collected at/around the time of delivery; vaginal swabs, and breast milk from mothers. Anticipated environmental samples include air, dust, soil, food, and water. .