Teen pregnancies—defined as pregnancies in women under the age of 20, regardless of marital status—in the United States decreased 28% between 1990 and 2000, from 117 pregnancies per every 1,000 teens to 84 per 1,000. Teenage birth rates peaked in 1991, when there were 61.8 births per 1,000 teens, and the rate dropped in 17 of the 19 years that followed. From 2009 to 2010, the teen pregnancy rate dropped 9%, the biggest one year drop since the 1940s.
Slightly more than half of Hispanic and black women will become pregnant before the age of 20. Asian-Americans have the lowest rate of pregnancy before the age of 20 of any ethnic group.
One in four women in America who had sex during their teenage years will have a baby before they are married, compared to only one in ten who wait until they are older. Even more will experience a pregnancy. Of women who have sex in their teens, nearly 30% will conceive a child before they are married, but only 15% of women who don't have sex in their teens will get pregnant. Of all women, 16% will be teen mothers.
International comparisons typically place US teen pregnancy and teen birth rates among the highest in the developed world. For example, a 2001 study by UNICEF found that the US teenage birth rate was the highest among 28 OECD nations in the review; in a 1999 comparison by the Guttmacher Institute, U.S. teen pregnancy and teen birth rates were the second-highest among the 46 developed countries studied. In 2002, the U.S. was rated 84th out of 170 World Health Organization member countries based on teenage fertility rate.
According to an international comparison by the Guttmacher Institute, teen pregnancy and childbearing levels are higher in the US largely because of differences in contraceptive use. Sexually active teens in the US are less likely to use any contraceptive method and especially less likely to use highly effective hormonal methods, primarily the pill, than their peers in other countries. The research also found that US teens who become pregnant are less likely to choose abortion, whether due to lack of access, higher levels of antiabortion sentiment, or greater acceptance of teen motherhood.