Sexual activity among young American women has soared in the last two decades to the point where more than half of those ages 15 to 19 have had premarital sex, federal health and behavior researchers reported Friday.

A new survey of women, conducted by the Centers for Disease Control, shows 51.5 of those ages 15 to 19 reported engaging in premarital sex. Those figures - from 1988 data - are nearly double the 28.6 percent for 1970.While the most current data show 25.6 percent of 15-year-old girls have had sex, the figure reaches 75.3 percent for their 19-year-old counterparts.

The findings are not good news for those hoping the '70s and '80s would prove to be more sexually conservative than the swinging '60s. If the message in this age of AIDS is that sex can be dangerous, many

young people apparently didn't get it, researchers said.

"This is happening during a time when we are putting so much emphasis on public-health messages regarding the risks of sexual activity, because of the AIDS crisis," said Dr. Sevgi Aral, a sociologist with the CDC's Center for Prevention Services. "That's why this is so concerning."

The explosion among young women starting sex is a product of our times, Aral said.

"We do not give very clear, uni-directional messages to our adolescents," she said. "We say, `Just say no. Delay the initiation of sex. Be monogamous.' But in a lot of our popular mass-media messages, we're putting so much emphasis on sexuality and glamorizing sexuality."

The advice to "just say no" goes beyond moral concerns; sex for young people - young women, in particular - can be dangerous, Aral said.

"Adolescence is a stage of life . . . where even people who later on end up being extremely monogamous may have several partners to start. And with each new partner, there's an increasing risk of being exposed to new sexually transmitted pathogens," she said.

Of the young women who initiated sexual intercourse before age 18, 75 percent reported having had two or more partners, and 45 percent reported having had four or more partners, the survey revealed.

The study also found that the older a woman was when she started having sex, the fewer sexual partners she had. "Among those who became sexually active after age 19, 20 percent reported having had more than one partner, and 1 percent four or more partners," researchers said.

Multipule partners can be especially risky for young women, who are more prone to cervical and vaginal infections because of early development of the cervix, she said. Older persons who are sexually active also may have built up some degree of immunity to some sexually transmitted diseases, she said.

The CDC, citing previous research, noted that by their late teens about 4 percent of white Americans and 17 percent of black Americans have been infected with herpes 2, a sexually transmitted virus.

In the CDC survey, the percentage of 15-year-old girls having had premarital sex at least once increased more than fivefold from 1970 to 1988, from 4.6 percent to 25.6 percent. For 17-year-olds, the increase was from 32.3 percent to 51 percent. For 19-year-olds, it was 48.2 percent in 1970 and 75.3 percent in 1988.

Rates were somewhat higher for black women than for white women; 58.8 percent of the black women ages 15 to 19 in 1988 had begun sexual activity, compared with 50.6 percent for their white counterparts.

The racial disparity was much greater two decades ago; in 1970, the rate was 46 percent for blacks and 26.7 percent for whites.

"For white adolescents, this represents an increase in the number of sexually experienced females from 2.2 million in 1970 to 3.7 million in 1988," while for black adolescents it went from 600,000 to 800,000, the Atlanta-based CDC said.

The survey was conducted in 1988 among 8,450 women between 15 and 44 years old. All were asked when they had first had sex, and the percentages were then plotted for ages 15-19, from 1970 to 1988.

Some women thus were asked to remember 18 years back, but the results are still believed to be largely accurate, Aral said. "For the majority of women, the initiation of sex is meaningful enough that they remember it correctly."

The survey was part of a study of women concerning reproduction and sexually transmitted diseases; no similar CDC study of young men was conducted.


GRAPHIC: Sexual activity

Female teenagers who have had sex:

Age 1970 1988

15 years old 4.6% 25.6%

19 years old 48.2% 75.3%

By Race


Blacks 15-19 years old 46.0%

Whites 15-19 years old 26.7%


Blacks 15-19 years old 58.8%

Whites 15-19 years old 50.6%