nearly 4 million kids who have at best one spouse that entered the u . s . unlawful were based in the united states and are p . s . citizens as a result , prior to the report developed by the pew hispanic center . that ' s about third percent of the estimated 5 . 5 billions babies of illegal immigrants of the u world , according to the study . about 1 . 8 million youth of mexicans immigration live in families , the study found .
Three quarters of U.S. illegal immigrants have children.