"I'm staying pregnant," Ellen Page announces with an air of defiance as the 16-year-old title character in "Juno," the current sleeper hit. Then, in often humorous episodes, audiences follow Juno through her plight — telling her parents, finding an adoptive couple, going to high school pregnant and enduring the ups and downs of her relationship with the baby's father.

In a span of about six months, Hollywood has given audiences three movies, each an endearing mix of humor and sentimentality, in which the main characters embrace pregnancy in less-than-ideal circumstances.

A few months earlier, moviegoers watched the unhappily married Jenna (Keri Russell) in "Waitress" deliver a baby whose arrival she had dreaded. Once the baby is born, she leaves her overbearing lunk of a husband and settles happily into single motherhood.

And in one of the summer's biggest hits, "Knocked Up," a career woman in her late 20s (Katherine Heigl) decides to go through with her pregnancy, the product of a one-night encounter with a jovial slacker (Seth Rogen). By the movie's end, the two become a couple, joined by the birth of their child.

Movies in previous generations featuring unplanned pregnancies tended to have a tragic quality, presented a bit like soap opera (1959's "Blue Denim", 1949's "Not Wanted "and 1946's "To Each His Own" are a few examples) or the stuff of grim, formulaic comedy (1995's "Nine Months").

Today, the impending, though unplanned, birth of a baby is fodder for comedy, romance and unexpected happiness.

WOMEN NO LONGER "VICTIMS"

"This is a sea change," says Leonard Maltin, film historian for "Entertainment Tonight." "It reflects what's going on in the world, which is that women no longer need to feel like victims, even if something as dramatic as this has happened. For decades the very phrase "unwanted pregnancy' was a synonym for 'soap opera.' There was no question what kind of film you were going to see: It was going to be weepy. That has changed enormously. We're now open enough in our willingness to deal with it and show that we can even laugh at it. These attitudes are in the zeitgeist, and the smarter, hipper movies tap into that."

What has changed over the years to make inadvertently expectant mothers the source of such optimistic expectations?

"It reflects a shift in morality and acceptance of young women who are not married having sex lives," says Jeanine Basinger, chair of film studies at Wesleyan University and author of "The Star Machine." "There is a difference in the cultural climate. The acceptance of keeping and raising a child if you're unmarried, or meeting and choosing the adoptive parents and discussing it openly, is a modern phenomenon."

Adds Maltin: "The reason these films resonate with audiences is that we can all relate to them."

Audiences particularly related to "Knocked Up," a summer blockbuster that grossed a hefty $148.8 million. Since opening last month, "Juno" is drawing large audiences and has taken in $85.4 million, which qualifies it as a bona fide art-house hit. And it's on the short list for Oscar nominations, to be announced Tuesday. "Waitress," which opened in May and was made on a shoestring, earned a modest $19.1 million but was a big film-festival favorite.

The stories each have an uplifting quality. In "Waitress," Russell's character and her young daughter go off hand in hand in a sweetly lilting ending, after what began as a rather grim tale. In "Knocked Up," audiences walk out having a sense that the baby will be loved and well taken care of. In "Juno," the baby is eagerly adopted by a warm-hearted woman (Jennifer Garner) who has been yearning to be a mother.

The protagonists in each of the films are endearing and smart. Rather than being portrayed as victims, they are all take-charge heroines with heart.

"What's interesting is the sweetness that they're bringing to these stories," Basinger says. "It's still the same old motherhood story. Once you remove the social stigma of the unwed mother, things change."

In movies of past decades, things were not so full of sweetness and light. The tabloid-style titles — "Girl in Trouble" (1963), "The Shame of Patty Smith" (1962), "Damaged Goods" (1961) and "You've Ruined Me, Eddie "(1959) — focus on tragedy and disgrace.

DELIVERING MORE HOPEFUL STORIES

Even more recent films, such as 1996's "Citizen Ruth" and 1982's "Fast Times at Ridgemont High," positioned unplanned pregnancies in a grim light.

"Generally speaking, in the old movies, if they were going to tell the story, it was darker and couched in sympathetic terms toward the pregnant woman," Basinger says. "But these days, the audience doesn't come in and have to be talked out of being judgmental. The audience is living with these issues. And with all the violent films out, people are finding some relief in these more human stories."

Judd Apatow, writer/director of "Knocked Up" (and "The 40-Year-Old Virgin"), agrees.

"The reason why people like these movies, and a common thread between them, is that people are happy to get a break and see stories which treasure the idea of children," Apatow says. "Especially because there are a lot of things happening in the world today that are very dark and that don't value human life. Children give you hope.

"In 'Waitress,' when she walks away at the end with her child, I bawl. It's powerful and hopeful."

But as life-affirming as each of these movies is, none of the stories follows the traditional path of a man and woman falling in love, marrying and having a child.

"I was just trying to present something that I had not seen before in movies or television," Apatow says. "My thought was about two people who don't seem to be as a good couple being forced to give it a try. I never thought in terms of not keeping the baby, because it went against my idea for the entire movie."

Apatow and the filmmakers associated with the other films deny any kind of political or social agenda. Their goal: create entertaining stories.

It's not surprising to learn that two of the three were written by young women. The late Adrienne Shelly wrote "Waitress" when she was 38, and Diablo Cody wrote "Juno" at 27.

"When I read 'Juno,' every time I thought I knew where the movie was going, it completely surprised me," says Jason Reitman, who directed the film. "The main thing I got from the screenplay was the evolution of the American family. If there's a trend right now, it's about acceptance. What we're struggling with right now politically has nothing to do with adoption or abortion at the end of the day. What we're struggling with is open-mindedness. These are a string of films in which the filmmakers are not passing judgment on their characters."

ABORTION AS AN INTERNAL DEBATE

In "Juno," Page goes to an abortion clinic but walks away. "I was thinking I'd just nip it in the bud," she says at first. Then, a bit later, in the film's distinctive teen-speak, she says: "I was thinking I could, like, have the baby and give it to somebody who totally needs it. Maybe they'll, like, canonize me for being totally selfless."

"Juno" producer Lianne Halfon says the film seemed to underscore people's already established opinions on abortion.

"When we read the script, one of the things we most responded to was the fact that it discussed teenage pregnancy and abortion without seeming to land on either side of the debate," Halfon says. "The thing we were trying for, and it was delicate to do, was have her decision be uninfluenced by any debate, except an internal one."

Halfon acknowledges that when she and the filmmakers were initially seeking financial backing for the film, the topic of abortion was off-putting.

"When we were first looking for financiers, the discussion of abortion and the fact that she seemed flip, people saw as a hot-button issue," Halfon says. "The combination of the dialogue and a pregnant teenager together with the word 'comedy,' people couldn't see how it would all come together.

"But this movie not only embraces the pregnancy, it embraces that she's a sexual being. And that's really unusual."

Michael Roiff, producer of "Waitress," stresses how he and Shelly, who also directed, wanted to tell a story that wasn't predictable.

"She treated sort of taboo subjects without the kid gloves," Roiff says. "She just didn't want to make another tired indie film. Adrienne wrote this while she was pregnant. She was feeling all these things, and she thought it was great material. Like, 'Is it OK not to be excited? Is it OK to be nervous?'

"We're taught to be quiet about these things. These things don't show up in the real world, and therefore they aren't echoed in film. We all have things we aren't excited about that we don't know how to get rid of and aren't willing to embrace. So it's a kind of universal story about having an obstacle in your life that no one else sees as an obstacle."

An agenda opposing abortion rights? Not a factor, Roiff says.

"It was just a lot more interesting to see her struggle against something," he says. "It was more interesting because she was fighting against the pregnancy the entire film, but she didn't take the route that would have essentially made that easier for her."

It's about art, not political statements, each of the filmmakers insists.

"People try to politicize these movies," Apatow says. "But they're all just human stories of people in very difficult situations. And we all root for people to do the right thing. That's why they're fun to watch. They're all women dealing with pregnancies happening at a moment when their relationships aren't working.

"But how their relationships aren't working is something completely different in each movie. And each version is completely interesting. I'm a big fan of all of them. You want everything to work out for Katherine Heigl and Keri Russell and Ellen Page. You're hoping that their lives will work out and that they will do well by the child."

EVER MINDFUL OF THE AUDIENCE

Still, none of these filmmakers is wearing blinders. The pitfalls and problems of unwanted pregnancies are not shied away from in each of the movies.

"All these movies present how difficult it is to be in this situation," Apatow says. "I'm sure there's room out there for the same type of movie where everything goes terribly wrong and it's tragic. I'm sure someone will make that movie. But it won't be me. I don't need to be that guy."

Apatow is of the mind that the majority of moviegoers want to escape the harsh realities of contemporary life.

"After working hard all week, people don't need to go to the movies on Saturday night and watch someone deciding whether to abort a fetus," he says. "They want to laugh and have a good time and see a story that lifts their spirits and gives them hope. I can watch a more thoughtful documentary on the subject to enlighten myself. I wouldn't look to the maker of '40-Year-Old Virgin' to teach me about all sides of the abortion crisis.

"I'm first in line to see the Mike Leigh movie about the abortionist ("Vera Drake"). But I'm trying to tell stories that make people feel better about their lives. That's why I like all these movies. It's fun to see a story that's handled honestly where you see people trying to do right by each other."