US children's study escapes knife
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* Janet Rae Brooks

*   © 2007 Canadian Medical Association

A massive study of the genetic and environmental causes of illness in American children is set to begin recruiting subjects next year after a late cash infusion from the US Congress.

The National Children's Study hopes to pinpoint causes of many diseases, including autism, asthma, diabetes and obesity, by tracking the health and environments of 100 000 children from the womb to their 21st birthdays.

Congress earmarked $69 million for the study in February, which exceeds the total amount spent on the project since its creation in 2000. The study was slated for termination under President George W. Bush's budget recommendations for the 2007 fiscal year.

Led by the US Department of Health and Human Services — through the National Institutes of Health and the Centers for Disease Control and Prevention — and by the Environmental Protection Agency, the study will cost an estimated $3.5 billion. Advocates say it is a bargain, considering the hundreds of billions spent annually to treat sick children in the United States.

Future funding is not certain. Bush's 2008 budget allocates no money to the study; Congress is funding it year to year.

Study participants have yet to be born. The study will be the first to examine prenatal exposures and then track offspring to adulthood. Researchers will start enrolling pregnant women and those of childbearing years in the summer of 2008.

Sampling statisticians selected 105 locations nationwide to ensure the study would include rural and urban children from a wide range of ethnic, racial and economic backgrounds. Enrolment will begin first at 7 Vanguard Centers selected in 2005. Most participants will be recruited door-to-door. Others will be enrolled through health clinics, hospitals or their doctors.

![Figure1](http://www.cmaj.ca/https://www.cmaj.ca/content/cmaj/176/12/1694/F1.medium.gif)

[Figure1](http://www.cmaj.ca/content/176/12/1694/F1)

Figure. The ambitious US National Children's Study hopes to track over 100 000 children from the womb through their 21st birthday. Photo by: Corbis/Magma

In March, hospitals, medical schools and local health departments in the selected areas were asked to submit proposals to operate 20 more study centres. Researchers will archive tissue samples, including placenta and baby teeth, from each child, and regularly collect environmental samples, such as air, house dust, backyard soil and drinking water. Samples will also be collected at the children's day-care centres and schools. Families will even be asked to freeze portions of home-cooked meals, so they can be analyzed for composition and contaminants. How the children are cared for, how often they see a doctor and the safety of their neighbourhoods will also be tracked.

Researchers will analyze data as it is collected, releasing the first results 2–3 years after launch. New questions are likely to emerge from early findings and will be addressed as the study continues. Findings could answer age-old nature-versus-nurture questions and inform treatment of childhood diseases for generations.