Majority of children live with two biological parents.

Nearly 45 million (61 percent) of the nation's 73 million children younger than 18 lived with their biological mother and father in 2004 regardless of the parents' marital status, according to a U.S. Census Bureau report released today.

Of these children, 42.7 million lived with both parents who were married to each other. Another 4.1 million lived with a biological mother and stepfather, according to Living Arrangements of Children: 2004. An additional 19.3 million children lived with one parent, with the majority of those (88 percent) residing with their mother.

There were 12.2 million children (representing 17 percent of all children) who lived with a stepparent, stepsibling and/or half sibling.

Among children in these "blended" families, 71 percent lived with at least a half sibling, 46 percent with a stepparent and 10 percent with a stepsibling.

By the U.S. Census Bureau