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，样本约为100，000名在美国出生的儿童。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的深远影响，例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;已知的持续接触情况，如非持久性农药的普遍水平或幼儿每天接触媒体的时间;以及环境因素或造成这种高影响条件的原因的证据。NCS的主要目的是调查环境暴露（化学、生物、物理、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。该研究的独特之处包括其重点是在怀孕的最早阶段（以及其后）的环境暴露和计划的暴露和结果测量的广度。国家统计局响应国会2000年《儿童健康法》的授权，即国家儿童健康与发展研究所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。NCS将采用国家概率抽样方法选择研究开展地点和参与者。抽样设计采用多阶段聚类方法。在第一阶段，从美国所有县中随机选择105个地点（通常对应于单个县）。其中7个地点作为初始或先锋地点，参与国家控制系统的试验阶段。由于本研究的重点包括评估妊娠早期暴露的影响，因此孕妇及其伴侣以及育龄妇女均构成了入组的初始目标人群。数据收集将结合面对面接触和远程收集方法，例如，电话、电脑或邮寄问卷。预期的接触频率（面对面或远程）大约是从1岁起每3个月一次，从5岁起每6个月一次，此后每年一次。对于参加研究的儿童样本，还将访问儿童保育和学校环境，以收集环境样本和观察数据。预期的生物样本包括母亲和儿童的血液、尿液、毛发和指甲剪;父亲的血液、尿液和毛发;脐带血、脐带和胎盘组织以及分娩时/分娩前后收集的胎粪;母亲的阴道拭子和母乳。预期的环境样品包括空气、灰尘、土壤、食物和水。国家儿童研究已经在美国30个研究地点开始招募。这项研究是美国有史以来规模最大的儿童健康长期研究。

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 . 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. The National Children's Study has initiated recruitment at 30 study locations around the United States. The Study is the largest long-term study of children's health ever conducted in the United States.