Contraceptive failure rates based on the 1988 NSFG.

Analysis of data from the 1988 National Survey of Family Growth--corrected for the underreporting of abortion--reveals that contraceptive failure during the first year of use remains a serious problem in the United States, contributing substantially to unintended pregnancy. The pill continues to be the most effective reversible method for which data were available (8% of users accidentally became pregnant during the first year of use), followed by the condom (15%). Periodic abstinence is the method most likely to fail (26%), but accidental pregnancy is also relatively common among women using spermicides (25%). Failure rates vary more by user characteristics such as age, marital status and poverty status than by method, suggesting the extent to which failure results from improper and irregular use rather than from the inherent limitations of the method.