Contraceptive Failure in the United States: Estimates from the 2006–2010 National Survey of Family Growth

Abstract

CONTEXT: Contraceptive failure rates measure a woman's probability of becoming pregnant while using a contraceptive. Information about these rates enables couples to make informed contraceptive choices. Failure rates were last estimated for 2002, and social and economic changes that have occurred since then necessitate a reestimation. METHODS: To estimate failure rates for the most commonly used reversible methods in the United States, data from the 2006–2010 National Survey of Family Growth were used; some 15,728 contraceptive use intervals, contributed by 6,683 women, were analyzed. Data from the Guttmacher Institute's 2008 Abortion Patient Survey were used to adjust for abortion underreporting. Kaplan‐Meier methods were used to estimate the associated single‐decrement probability of failure by duration of use. Failure rates were compared with those from 1995 and 2002. RESULTS: Long‐acting reversible contraceptives (the IUD and the implant) had the lowest failure rates of all methods (1%), while condoms and withdrawal carried the highest probabilities of failure (13% and 20%, respectively). However, the failure rate for the condom had declined significantly since 1995 (from 18%), as had the failure rate for all hormonal methods combined (from 8% to 6%). The failure rate for all reversible methods combined declined from 12% in 2002 to 10% in 2006–2010. CONCLUSIONS: These broad‐based declines in failure rates reverse a long‐term pattern of minimal change. Future research should explore what lies behind these trends, as well as possibilities for further improvements.