Intended and unintended births in the United States: 1982-2010.

OBJECTIVES: This report shows trends since 1982 in whether a woman wanted to get pregnant just before the pregnancy occurred. This is the most direct measure available of the extent to which women are able (or unable) to choose to have the number of births they want, when they want them. In this report, this is called the "standard measure of unintended pregnancy." METHODS: The data used in this report are primarily from the 2006-2010 National Survey of Family Growth (NSFG), conducted by the Centers for Disease Control and Prevention's National Center for Health Statistics. The 2006-2010 NSFG included in-person interviews with 12,279 women aged 15-44. Some data in the trend analyses are taken from NSFG surveys conducted in 1982, 1988, 1995, and 2002. RESULTS: About 37% of births in the United States were unintended at the time of conception. The overall proportion unintended has not declined significantly since 1982. The proportion unintended did decline significantly between 1982 and 2006-2010 among births to married, non-Hispanic white women. Large differences exist between groups in the percentage of births that are unintended. For example, unmarried women, black women, and women with less education or income are still much more likely to experience unintended births compared with married, white, college-educated, and high-income women. This report also describes some alternative measures of unintended births that give researchers an opportunity to study this topic in new ways.