The Ramsey County arm of the National Children's Study -- a decades-long effort to learn the genetic, social and environmental origins of asthma and other diseases -- has reached a milestone with the birth of the first baby from a participating family.

Since January, researchers at the University of Minnesota have been recruiting as many as 100 women who are likely to have children in the near future into an early test phase of the study. Fifty women agreed to participate so far, and just last week the researchers learned that one of those enrollees had given birth.

It was a small but exciting step forward, said Patricia McGovern, the lead investigator for the local arm of the national study, which is also taking place in 36 other regions of the country.

Eventually, the local arm of the study will enroll thousands of families in targeted zip codes in Ramsey County and will be following the health of newborn children from those families until they turn 21. In all, the NCS intends to recruit 100,000 people -- making it the largest study of children's health in U.S. history. (Recruiting could take place in seven other Minnesota counties as well.)

Through an exhaustive collection of health data and physical materials -- from the cord blood of the newborns to the dust from the vacuum cleaners in their homes to the drinking water from their faucets -- the researchers hope to understand exactly why some children are more at risk for illness and disease than others.

"They will be part of a landmark study," said Deborah Hendricks, who is involved in NCS recruiting. "This study will not be repeated again in this century."

It is generally presumed that Ramsey County was selected because of its thriving Hmong population. Leaders of the federally funded study are going to great lengths to recruit families that are representative of the nation as a whole.

The test phase of the study will determine the best methods for recruiting families and collecting data when the full study is launched. The recruiting strategy being used in Ramsey County involved mailings to 31,000 random addresses and appearances by recruiters at community events and fairs. (Another round of mailings are going out in an effort to gain 50 more enrollees into the test phase.)

This recruiting approach will be compared for its cost and its effectiveness with approaches used in other regions. Some regions simply worked through local obstetrician offices to find women of childbearing age to enroll. McGovern said each recruiting strategy has its own biases that need to be evaluated as well. Random mailings are inexpensive, she said, but also likely to attract more affluent and science-minded women who are eager to participate. Certain segments of the population can be missed by that approach.

Even dust collection is being evaluated in the test phase -- as researchers are comparing whether they get better results using dust wipes or simply taking the vacuum bags out of people's homes, McGovern said. (Dust is a great indicator of environmental hazards in a home.)

While children in the study will be followed for two decades, researchers expect to gain results much earlier than that. For example, they will be able to compare the environmental, social and genetic data from families to determine what puts women at greater risk of giving birth to children prematurely or at low birthweights.

Researchers stressed that the process will be voluntary and confidential for families -- who can refuse any test or request and can drop out of the study at any time. They anticipate that families will become engaged in the study over time and that the dropout rate will be low. The program includes some incentives, including retail gift cards, to reward families for participation.

More information on the local study can be found on its Facebook page.