A new study updates failure rates for the reversible contraceptive methods most commonly used in the United States. These rates provide important information to help couples make informed contraceptive choices. According to "Contraceptive Failure in the United States: Estimates from the 2006–2010 National Survey of Family Growth," by Aparna Sundaram of the Guttmacher Institute et al., within the first 12 months of typical use, long-acting reversible contraceptives (the IUD and implant) have the lowest failure rates of all methods (1%), while condoms and withdrawal carry the highest probabilities of failure (13% and 20% respectively). However, the failure rate for the condom has declined significantly since 1995 (from 18%).

The authors found significant improvement in contraceptive failure rates between 1995 and 2006–2010. The likelihood of failure for any method use declined from 14.9% to 10.3% during this period, while the rate for all hormonal methods combined declined from 8% to 6%.

"Contraceptive failure rates can help inform strategies for providers to improve contraceptive service provision, and can help women and their partners choose the method most suited to their needs," said Sundaram, a senior research scientist with the Guttmacher Institute. "Guaranteeing that couples have access to the full range of contraceptive methods, and education so they can use those methods effectively, is critical to ensuring continued declines in unintended pregnancy."

Sundaram and her colleagues found significant differences in the likelihood of contraceptive failure among certain demographic subgroups:

• The contraceptive failure rate was much lower among users of any method with no children (5%) than among those with one child (14%) or with two or more children (15%).
• Black and Hispanic women had higher probabilities of method failure than white women for all methods combined, the pill and condoms.
• Poor women had significantly higher failure rates than women whose incomes were at least twice the poverty level for all categories of methods.

The study did not address reasons behind the declines or the continued disparities between groups. The authors suggest additional research is needed to understand what is driving the trends and to determine how to further improve failure rates.

"Public health efforts over the past decade have bolstered reproductive health services and expanded women’s access to the full range of contraceptive methods, ensuring they are able to choose the method that best meets their needs," said Kathryn Kost, coauthor and director of domestic research with the Guttmacher Institute. "These efforts have also likely played a role in helping individuals to use contraceptives more effectively, thereby reducing failure rates."

The study relied on nationally representative data from the 2006–2010 National Survey of Family Growth to determine the typical-use failure rates in the first 12 months of initiating method use. Typical use refers to the way a method is actually used by women and their partners, including inconsistent or incorrect use. This contrasts with perfect-use failure rates, which are estimated during clinical trials.