82: Trends in adolescent sexual experience, contraceptive use, and pregnancy risk, 1995 and 2002

Abstract

Since the early 1990s, teen pregnancy and birthrates declined have declined dramatically in the United States. A previous study for these declines in U.S. teen pregnancy rates - based on data from high school students - suggested equal contributions for delayed initiation of intercourse and improved contraceptive use. The National Survey of Family Growth (NSFG) is a periodic national probability study of the non-institutionalized population in the United States. The NSFG provided data on sexual activity and contraceptive use at last intercourse among teens aged 15-19 years for 1995 (n=588) and 2002 (n=444). These data were combined with method-specific contraceptive failure rates (CFRs) derived from the 1988 and 1995 NSFG to calculate the risk of pregnancy based on a previously developed weighted-average contraceptive failure rate (WACFR) index. NSFG provides data on up to four methods of contraception at last intercourse. Between 1995 and 2002, sexual experience (i.e., ever had sexual intercourse) declined from 51.7% to 46.8%. Recent sexual intercourse (i.e., intercourse during the past 3 months among teens who had ever had intercourse) did not change over time (79% to 81% respectively). Use of no method of contraception declined (31% to 18%) while use of multiple methods increased. In 1995, 17% of users reported using 2+ methods and 1% reported 3+ methods, compared to 32% and 3%, respectively, in 2002. Changes in contraceptive use from 1995 to 2002 included increases in condom use at last intercourse (38% to 53%), pill use (25% to 32%), use of injection (7% to 10%), and use of withdrawal (7% to 11%). The risk of pregnancy based on contraceptive use alone declined 32% between 1995 and 2002, while risk based on sexual experience alone declined 9.5%. These data suggest that both delayed initiation of sexual intercourse and improved contraceptive practice contributed to declines in pregnancy rates among teens between 1995 and 2002. Improved contraceptive use included increases in dual use and use of many individual methods.