THURSDAY, Nov. 30, 2006 (HealthDay News) -- The number of American teenage girls who are becoming pregnant has dropped dramatically since 1990, and researchers say an increase in the use of condoms among teens may be the reason why.
The finding suggests that teens are increasingly turning to contraception as a means of avoiding early pregnancy, even as conservative groups point to abstinence as the only sure means of doing so.
"It is remarkable that teens are becoming better contraceptors even as there are efforts afoot to reduce the information and skill-building that they receive about contraception," said Freya L. Sonenstein, a professor and director of the Center for Adolescent Health at Johns Hopkins Bloomberg School of Public Health.
She was not involved in the study, which was conducted by researchers at Columbia University and the Alan Guttmacher Institute, both in New York City. Their report is published in the Nov. 30 online issue of the American Journal of Public Health.
Federal statistics show that pregnancy rates among U.S. girls aged 15 to 19 have dropped by 27 percent between 1991 and 2000, and birth rates for this group fell by 33 percent between 1991 and 2003.
However, the exact reasons for this trend have remained unclear. In their study, researchers led by Columbia's Dr. John S. Santelli examined data for the years 1995-2001 from the ongoing National Survey of Family Growth.
They specifically looked at trends in sexual behavior and contraceptive use for nearly 2,600 U.S. girls, aged 15 to 19, who were interviewed as part of the survey. The researchers' hoped to determine the roles of abstinence and contraception in the ongoing decline in teen pregnancy.
Santelli's team found that 86 percent of the decline in pregnancy was associated with increased use of contraception. There was increasing use of both birth control pills and condoms, or the use of dual methods such as the pill and a condom combined.
Only 14 percent of the decline in pregnancy was attributed to reductions in teens' sexual activity, the researchers noted.
In addition, Santelli's group developed a "contraceptive risk index" to account for effectiveness of contraceptive use. They also developed an overall "pregnancy risk index" calculated by the contraceptive risk score and the percentage of teens reporting sexual activity.
These data revealed that, among teens 15 to 17 years old, 77 percent of the drop in pregnancy was due to more contraceptive use and 23 percent to reduced sexual activity.
Based on their findings, the researchers believe that contraception may be the best way to further reduce the number of teens getting pregnant.
"Abstinence promotion is a worthwhile goal, particularly among younger teenagers; however, the scientific evidence shows that, in itself, it is insufficient to help adolescents prevent unintended pregnancies," the researchers wrote. "The current emphasis of U.S. domestic and global policies, which stress abstinence-only sex education to the exclusion of accurate information on contraception, is misguided," they concluded.
American boys and girls are delaying sexual activity, Sonenstein noted. "Indeed, one of the unanticipated trends is the decline in sexual activity among male teens who no longer show higher rates of sexual experience compared to female teens," she said.
Sonenstein believes that contraception use and delayed sexual activity work hand-in-hand to prevent unwanted pregnancy among teens.
"While it may be useful to think about the delay of sexual activity and increased contraceptive use as unrelated behaviors, research tells us that the older teens are at sexual initiation, the more likely they are to use contraception," Sonenstein said. "Thus, prevention efforts should emphasize both the need to reduce sexual activity and to use contraception when activity occurs."
There's more on the hazards of teen pregnancy at the March of Dimes.