When I see this and the story about people living with their parents an extra 10-12 years, it seems to me like two expressions of a single trend.

Arielle Wilcott, 17, knows the facts of life. Her mother gave her the "birds and the bees" talk for the first time when she was 13, and the two women continue an open dialogue on love, sex and relationships.

Several years ago, Arielle's junior high school in Sherman, Tex., brought in a health educator to discuss sex, sexually transmitted diseases and birth control. At the end of ninth grade, Arielle and her classmates participated in an assembly that encouraged abstinence.

Combined with what she has read, seen on television and discussed with her friends, Arielle said she believed that she had been thoroughly "sex educated." That is why she has decided to wait to have sex until she grows older.

"I don't want to be forced to take care of a child that I'm not ready for or get an S.T.D.," said Arielle, a high school senior who likes art and plans to be an animator after college.

"As far as sex," she said, "it'll happen someday, but just not today. Besides, if I came home pregnant, I'd be lying on the ground, outlined in chalk." [P6: I wonder how large this figured in her position]

Like Arielle, a record number of teenagers have received the message, "Don't bring home a baby." Last week, the Centers for Disease Control and Prevention, in its annual tally of birth statistics, announced that the teenage birthrate had declined 30 percent over 10 years to a historic low of 43 births per 1,000. African-American teenagers showed the sharpest declines, down more than 40 percent since 1991. For young black teenagers, from 15 to 17, the rate was half, to 40 births per 1,000 in 2002 from 83.6 per 1,000 in 1991 .

These declines, combined with a decrease in abortions among teenagers, points to a promising trend: fewer teenagers are becoming pregnant. According to the Alan Guttmacher Institute, in women 15 to 19, the pregnancy rate dropped from 11.5 per 1,000 in 1991 to 8.5 in 1999, the latest year with available statistics.

"When you see the abortion rate decline in tandem with birthrate, this essentially means that teenagers are being more successful in avoiding pregnancy, both that end in abortion and end in birth," said David Landry, senior research associate at the institute. It estimates that in women 15 to 19, the abortion rate declined, from 40 per 1,000 in 1990 to 24 in 1999.

Experts in the field agree that educational efforts have been crucial to reducing the numbers.

…Even as advocates, health educators and, of course, parents, celebrate the good news, the debate continues over what type of sex education can take credit.

The two sides are firm.

Abstinence-only education, which the Bush administration supports, teaches that refraining from sex is the only way to prevent pregnancy and diseases. Programs that receive federal financing are not allowed to advise using contraception to reduce the risk of pregnancy or condoms to protect against disease. In 2003, the federal government devoted $117 million to abstinence education.

Comprehensive sex education, on the other hand, teaches that while abstinence is preferable, young people need information about sex and contraception. The Guttmacher Institute says that two-thirds of public school districts have policies to teach sex education, and that 35 percent of those require that abstinence be promoted as the sole option for unmarried people. Birth control and condoms can be mentioned just in terms of failure rates.

Arielle Wilcott says her ninth-grade workshop encouraged just abstinence until marriage, while presenting failure rates for birth control.