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 periodicall