Women in the United States are having children later, fewer of them are married and the percentage of teenage mothers of newborns has dropped since 20 years ago, Reuters quoted a new report as saying. In 1990 only nine percent of births were to women 35 years and older and 13 percent were to adolescents, but the numbers had shifted by 2008 when 10 percent of births were to teens and 14 percent were to older women. "The demography of motherhood in the United States has shifted strikingly in the past two decades," the Pew Research Center said in the report. "Another notable change during this period was the rise in births to unmarried women ... a record 41 percent of births in the United States were to unmarried women, up from 28 percent in 1990," it added. The share of births to unmarried mothers has increased most among white and Hispanic women. Mothers are also better educated than they were two decades ago. In 2006 more than half of mothers of newborns had some college education, an increase from 41 percent in 1990. The percentage was even higher among mothers 35 years and older with 71 percent. "The higher share of college-educated mothers stems both from their rising birth rates and from women's increasing educational attainment," the report explained. Attitudes have also altered in the past 20 years as the stigma of unmarried parenthood has softened and Americans have married later in life. But two is still the ideal number of children in a family for many Americans, which hasn't changed since the 1970s and many couples cited "the joy of having children" as the reason for starting a family. "However, a half century after the Food and Drug Administration approved the sale of birth control pills, nearly half of parents said 'there wasn't a reason; it just happened."