Happy Surrogate Mother’s Day

The funny thing about “Baby Mama” is that the laughs don’t come when you expect them to. They wait awhile. In the meantime, the film makes room for character development and plot twists that turn an odd premise into a rewarding comedy, one that wins through insight and not idiocy. Most of the comedy in “Baby Mama” emerges from plausible events written with control, opportunity and thoughtfulness for its characters. I’m explaining that because it’s actually not as easy as it looks: With all those celebrity cameos, you’d assume that this is one of those films that surrenders to the evils of all-star silliness.

Actually, it is kind of silly now and then, but those highlights are justified by Tina Fey, who plays it so straight that it’s funny. She exists as the voice of reason in a madhouse: Without her, the film would’ve been crazier and desperate for laughs. The fact that she lives in a world with all those strange people puts us entirely in her corner, earning our sympathy by pressing on through one mishap after another. The movie challenges her but doesn’t degrade her and before the film is over, she will discover success in a disappointing world.

Fey plays Kate Holbrook, a 37-year-old working girl whose biological clock is ticking. She wants a baby, but her anatomy isn’t functioning properly and it’s hard for single women to adopt. The only choice left is to employ a surrogate mother named Angie (Amy Poehler), who lives out of town with her uncouth husband, Carl (Dax Shepard). They’re a trashy couple who need money quick.

Kate’s willing to give it to them: She hires her and promises that she’ll keep in touch, but then Angie and Carl have a fight and she begs to move in with her. She lets her stay, but there’s something about Kate that gets on Angie’s nerves. It could be the way she follows Angie all over the apartment and puts coasters wherever she has a drink, or maybe it’s the exotic groceries Kate keeps in her kitchen. Beggars can’t be choosers, though.

Kate already has her hands full with Angie by the time she meets Rob (Greg Kinnear), a guy who runs his own store selling fruit juice. He’s kind of cute, but Kate has lots of trouble dating guys: Whenever she mentions her dream of becoming a mother, they usually run for the hills.

The movie works because it’s true to the stars. The chemistry between Fey and Poehler is the key element here: Fey sets them up, Poehler knocks them down. Like the various asides they used to have during the “Weekend Update” sketches on “Saturday Night Live,” their comedy in “Baby Mama” feels like a balancing act where both halves get together and make the material work.

They’re not the only ones, though. The film includes appearances from Sigourney Weaver as a rich entrepreneur and Steve Martin as Kate’s boss. Weaver plays the surrogacy agent who works with Kate, but she seems more like Superwoman, given the fact that she can procreate well into her 50s. Martin plays the boss as a new-age liberal whose affection for the environment is such that a seashell inspires his latest project. These characters are already funny, but the performances give them enough impetus to steal the show.

When “Baby Mama” premiered some time ago, it was up against “Harold & Kumar Escape from Guantanamo Bay.” “Baby Mama” made more money, possibly because it appeals to the kind of women who take their dates to the movies. Fey disagrees, though: “Women drive what’s on television,” she says in Vanity Fair, “and husbands and boyfriends decide on movies.” Angie might’ve told her to shut up and pass the popcorn.