Teen models Jourdan Dunn, left, and Chanel Iman are shown on the cover of the November 2009 issue of Teen Vogue in this magazine cover image released by Teen Vogue. Dunn, 19, reveals in a story in the magazine that she is pregnant and is expecting a boy in December. Some parents worry about the message the magazine is sending to its readers about teen pregnancy.

Dallas ? A model on the November cover of Teen Vogue is a 19-year-old who reveals in the magazine that she is pregnant.

Jourdan Dunn is not visibly pregnant on the cover, and Teen Vogue Editor-in-Chief Amy Astley said the magazine didn’t know about Dunn’s pregnancy until after the photo shoot. But she said that editors didn’t consider pulling the cover Dunn shares with fellow model Chanel Iman.

“Teen pregnancy is a difficult, real-life issue that Teen Vogue readers (with an average age of 18) are mature enough to be exposed to,” Astley said in a statement. “Teen Vogue felt it was important to support, not punish, Jourdan Dunn, who contributed to a beautiful photo shoot and who will surely have an ongoing and successful career in fashion.”

The cover has raised eyebrows among some parents, teens and advocates against teen pregnancy.

“There’s no message to send to them that that’s not OK. Maybe if she’s on the cover to tell them ‘Be careful,’ that’s one thing,” said Catherine Essig, a 19-year-old sophomore at Dallas’ Southern Methodist University, who was concerned about 15- and 16-year-old readers.

Many advocates said parents should use the cover as a way to talk to their kids about sex and the importance of planning pregnancies for the right moment in their lives.

“Teen parenting isn’t glamorous, even if you are a teen model,” said Valerie Huber, executive director of the National Abstinence Education Association.

A message left by The Associated Press at Dunn’s New York City agency was not immediately returned. The London native told Teen Vogue that her unplanned pregnancy has been hard.

“All I could think about was what my mom was going to say, my agency, my boyfriend,” said Dunn, who is expecting a boy in December. “When I told my mom, she started crying and blaming herself. She got pregnant with me at the same age, and she said, ‘I don’t want you to have to go through what I did.”‘

The magazine should be used as a teachable moment because the media and popular culture help shape “the social script for teenagers,” said Bill Albert, a spokesman for the National Campaign to Prevent Teen and Unplanned Pregnancy.

“It shapes what they think is cool, is not cool, what’s in, what’s out, what’s acceptable, what seems to be the social norm,” he said. “It’s not the only influence and I’d suggest not the most powerful, but it is an influence.”

But parents, he said, shouldn’t underestimate their own power.

“Young people tell us time and time again that parents — not the media, not their partners, not their peers — parents most influence their decisions about sex,” he said.

After a record high in the early 1990s, the teen birth rate in the U.S. dropped 34 percent from 1991 to 2005. But between 2005 and 2007, it increased 5 percent, according to the National Campaign to Prevent Teen and Unplanned Pregnancy.

A lack of family planning remains a problem even as women get older — 70 percent of pregnancies among 18 to 29-year-olds are unplanned, Albert said.

The magazine cover story mainly focuses on the two models’ friendship, which grew chilly over competition for a time, and their experiences as black models in the fashion world.

Jill Taylor, chair of the women and gender studies department at Simmons College in Boston, said that she would have liked to have seen the magazine use the model’s pregnancy to provide more information about teen pregnancy.

“Fourteen and 15-year-olds reading it don’t have an idea how hard it is for most single mothers having babies. She’s got resources,” Taylor said.

That difference between Dunn and most teens could be a starting point for a discussion about timing.

“What do you want to have in place when you get pregnant?” asked Dr. Janet Realini, president of the Healthy Futures, a nonprofit dedicated to preventing teen and unplanned pregnancies in San Antonio and Texas. “For teens, we mostly want them to think about staying in school, finding the person who is right for them.”