"Knocked Up" is a comedy about pregnancy and parenthood -- for men.

		'Knocked Up' Starring: Seth Rogen, Katherine Heigl. Director: Judd Apatow. Rating: R for sexual content, drug use and language. Web site: http://www.knockedupmovie.com/ Related story: Movies nurturing a baby boom

That's why it's called "Knocked Up." And why Katherine Heigl, who plays Dr. Izzie Stevens on "Grey's Anatomy" and here is an aspiring entertainment reporter, gets drunk and hooks up with slacker Seth Rogen (as opposed to, say, Nick Lachey or a man who actually has a job).

And why the men are so juvenile and why fatherhood is such a scary concept for guys who act like they're 16 years old. And why a female character uses a four-letter word that women almost never utter, not even the dancers at the Bing on "The Sopranos."

None of that will matter to "The 40-Year-Old Virgin" crowd who will lap this up as if it were free beer. Free imported, icy cold beer, with the promise of pizza or chips.

"Knocked Up" stars Heigl as Alison Scott, a behind-the-scenes staffer at E! Entertainment. But she's about to get the chance to appear on camera, which is cause for celebration with her older sister, Debbie (Leslie Mann), a married mother of two.

They head to a club, which is how Alison meets Ben (Rogen), and where too much alcohol leads to what Borat would call "sexy time." But in the clear light of day, Alison realizes how little she has in common with Ben as he shares his secrets for a hangover cure -- vomiting and "weed" -- and his work. He and his roomies are creating a Web site that tracks nudity in movies.

But eight weeks later, when Alison develops morning sickness at a most inappropriate time, she realizes she and Ben just may have something or someone in common. "Knocked Up" tracks her pregnancy, the reaction of friends and family, and a coincidental blip in the marriage of Debbie and her sometimes secretive husband (Paul Rudd).

Judd Apatow, who made his feature-directing debut with "The 40-Year-Old Virgin" starring Steve Carell, wrote, directed and produced "Knocked Up."

Nobody knows boy banter like Apatow, whether it was his "You know how I know you're gay" routine in "Virgin" or the Dirty Man Competition here revolving around beard growth, "Back to the Future" and "Everybody Loves Raymond" references and the reaction to a most untimely visit to the delivery room. Let's just say you'll never see that image on "Grey's Anatomy."

Parts of "Knocked Up" are very funny, although the sharp E! Entertainment angle is nearly abandoned. Much is juvenile and sometimes crude. Some of it, especially the closing credits accompanied by pictures of blissful parents and newborns, is downright gooey and life-affirming.

But all of it is way too long.

This feels like the world's longest pregnancy or comedy, with a running time of 129 minutes. "Knocked Up" is like a helium balloon with a slow leak that quits hugging the ceiling and starts sliding down the wall the longer it goes.

No matter how good Heigl and Rogen are, I'm not sure I ever bought the Alison-Ben coupling. The male roomies, as played by Jay Baruchel, Jonah Hill, Jason Segel and Martin Starr, are a slam dunk, as are Mann, Rudd and little Maude and Iris Apatow as their adorable girls who also happen to be the director's daughters.

Despite the presence of the "Grey's Anatomy" star, "Knocked Up" is a manedy. That's a comedy aimed at men but containing enough interest for women to qualify as a date movie. Women may pine for Rudd and wish they looked like Heigl, but the men will get the last and best laughs.