"In 2006, 38 percent of all births were to unmarried women, up from 37 percent in 2005. Between 1980 and 2006, the percentage of births to unmarried women rose sharply for women in all age groups. Among teenagers, the percentage rose from 62 to 92 percent for ages 15–17 and from 40 to 81 percent for ages 18–19. The percentage tripled for births to women in their twenties, from 19 to 58 percent for women ages 20–24 and from 9 to 31 percent for women ages 25–29. The percentage of births to unmarried women in their thirties more than doubled from 8 to 18 percent.2
The percentage of children under age 18 living with two married parents3 fell from 77 percent in 1980 to 68 percent in 2007.4 In 2007, 23 percent of children lived with only their mothers, 3 percent lived with only their fathers, 3 percent lived with two unmarried parents, and 4 percent lived with neither of their parents."



childstats.gov