By N.C. Aizenman

Washington Post

WASHINGTON - The number of children born in the United States to illegal immigrants has dramatically risen over five years from 2.7 million in 2003 to 4 million in 2008, according to a study released yesterday. The report by the nonpartisan, Washington-based Pew Hispanic Center also found that more than a third of such children were in poverty in 2007, compared with about 18 percent of those born to either legal immigrants or U.S.-born parents. Similarly, one in four U.S.-born children of illegal immigrants had no health insurance in 2008, compared with 14 percent of those born to legal immigrants and 8 percent born to U.S.-born parents.

The findings suggest that the impact of the unprecedented spike in illegal immigration over the last three decades will continue to be felt for years, even as the size of the illegal-immigrant population itself appears to have leveled off since 2006 at about 10.4 million adults and 1.5 million children. Children born on U.S. soil are automatically granted citizenship.

The study, which analyzed census statistics, found that U.S.-born children now account for 73 percent of all children of illegal immigrants. And children of illegal immigrants - including those born overseas - now account for 6.8 percent of elementary- and secondary-school students nationwide and more than one in 10 students in Arizona, California, Colorado, Nevada, and Texas.

The Census Bureau does not ask people their immigration status. So the authors used a technique that essentially estimates the number of legal immigrants using other government records such as visas issued, then subtracts that population from the total number of foreign born counted by the census to come up with the number of illegals.

The spike in births to illegal immigrants is largely due to their relative youth compared with the general population.