CONTEXT:The high level of unintended fertility in the United States is a serious public health issue. Whether unintended fertility occurs across the population or is concentrated among a subset of women who experience multiple unintended births is unclear.

METHODS:Data from the 2002 National Survey of Family Growth were used to determine levels of unintended, unwanted and seriously mistimed childbearing, and chi-square and t tests were used to identify group differences in these measures, in two cohorts of women (those born in 1958–1962 and those born in 1965–1969). Both births (by ages 33–37) and mothers were used as units of analysis.

RESULTS:The proportion of births identified as unintended was greater in the 1965–1969 cohort than in the earlier cohort (37% vs. 34%), largely because a higher proportion of births to women in the former cohort were unwanted. In both cohorts, more than a third of women (36–41%) reporting at least one unintended birth had had at least one more, and women reporting unintended or unwanted births had higher overall fertility than others. Levels of repeat unintended fertility were greatest among black women, and the proportion of blacks who reported two or more unwanted births was 94% higher in the 1965–1969 cohort than in the 1958–1962 cohort (19% vs. 10%).

CONCLUSIONS:Repeat unintended fertility is common, especially among black women, who may differ from other groups in their contraceptive and fertility decisions as well as in their access to and ability to afford family planning services.