More than half of American teens ages 15 to 19 have engaged in oral sex, increasing to nearly 70% for those who are 18 and 19, according to the largest federal study of the nation's sexual practices.
The study also found that 11% of women ages 18 to 44 reported having at least one homosexual experience in their lifetime, up from 4% in a similar survey conducted in 1992.
Taken together, the two findings suggest a shift in sexual practices, in which females are using oral and lesbian sex "as a safer alternative than [vaginal] sex with men," said epidemiologist William D. Mosher of the National Center for Health Statistics, the study's lead author.
"If it is seen as a safer alternative, it is an interesting response to the campaigns to reduce teen pregnancy and to reduce sexually transmitted diseases and HIV," he said.
However, only 9% of the teens reported using condoms during oral sex. Studies have shown that gonorrhea, syphilis, genital herpes and human papillomavirus can be transmitted in this manner.
"They have not been given a strong enough message about the health risks of oral sex," said Dr. Claire Brindis of UC San Francisco.
James Wagoner, president of Advocates for Youth, a reproductive health organization in Washington, D.C., said the study showed that society was undergoing a social transition, with women and girls becoming more sexually confident.
"It calls into question the stereotype of boys as hunters and girls as prey," he said. "Something going on here is creating more balance between the sexes than we have seen before."
But Brindis cautioned that some of the apparent increases may simply represent an increased comfort level in discussing sexual behavior rather than an increase in activity.
Some may now "be disclosing information that had probably occurred for decades," she said.
Economist M.V. Lee Badgett, a visiting scholar at UCLA and research director of the Institute for Gay and Lesbian Strategic Studies, echoed that sentiment. "The world has changed in 10 years," she said.
Badgett noted that the 1990 census showed 150,000 households of same-sex couples in the nation, but 600,000 were reported in 2000. In both cases, she said, the differences "are much more likely to be due to a willingness to report than to an increase in numbers."
The yearlong study, which began in March 2002, involved in-home interviews of 12,571 people conducted by female researchers. The most recent similar study, a decade earlier, involved 3,300 interviews.
