When Tina Fey and Amy Poehler were named the first female anchor team on Saturday Night Live's "Weekend Update," they became the news. Their pairing was seen as a crack in comedy's glass ceiling, where male performers and guy-centered humor still dominate. As the stars of a big-budget comedy in the Judd Apatow era (where a woman's role is to make a man better), they're being heralded again. But what they're doing is not earth shattering, just funny.

Written and directed by their SNL colleague, Michael McCullers, Baby Mama is tailor-made to their strengths and sensibilities. The comic personae of this odd couple mesh perfectly with their characters: the uptight Fey, with her tendency to over-think everything and say too much, is the driven, self-sacrificing vice president of a good-for-you grocery chain; and the quicksilver Poehler, with her reckless physicality and whip-smart delivery, is the more capable than she appears white trash opportunist with a heart of gold.

McCullers views the union of infertile Kate Holbrook (Tina Fey) and surrogate mother Angie Ostrowiski (Amy Poehler) as a platonic romantic comedy, creating the gynocentric version of a bromance. The insemination scene is set to "Endless Love" (mercifully not "She's Having My Baby"), indicating that the relationship between the women is the main course, with men on the side. (The defiantly dense Dax Shepard is Angie's very common law husband Carl, and Greg Kinnear employs his low-boil charisma as smoothie entrepreneur Rob Ackerman, Kate's new crush.)

When Angie moves into Kate's tony Philadelphia apartment for the duration of her pregnancy, the comedic chemistry crackles, with jokes that are both highbrow (organic food is "crap for rich people who hate themselves") and low (a novel use for Pam cooking spray). Michael McCullers follows the method Tina Fey employs on her NBC sitcom 30 Rock, casually tossing out humorous bons mots; if you catch the joke, that's great, but they're already on to the next one.

Baby Mama showcases just enough of Steve Martin as Kate's tyrannically blissed-out boss, hippie capitalist Barry Steingart, and Sigourney Weaver's smugly fertile surrogacy coordinator Chaffee Bicknell, with first-time director McCullers deftly balancing the disparate performing styles. But his strength with actors doesn't compensate for a flat, utterly perfunctory visual style, and he tags on the kind of wish-fulfillment ending that negates all the hardships of these smart, zippy characters.

This accessible comedy is by no means revolutionary; a major influence is 1987's Baby Boom, with Diane Keaton as a yuppie who inherits an infant and ends up having it all despite herself. But Tina Fey and Amy Poehler have taken the female bonding movie to the next level, perhaps planting the seeds for the baby Mamas to come.

© 2008, Serena Donadoni. All rights reserved.

Writer and director: Michael McCullers | Cinematography: Daryn Okada | Music: Jeff Richmond | Production Design: Jess Gonchor | Costume Design: Renée Ehrlich Kalfus | Editing: Bruce Green | Producers: Lorne Michaels and John Goldwyn | Released by Universal Pictures | Running time: 96 minutes | Rated PG-13

Cast: Tina Fey (Kate Holbrook), Amy Poehler (Angie Ostrowiski), Steve Martin (Barry Steingart), Sigourney Weaver (Chaffee Bicknell), Greg Kinnear (Rob Ackerman), Dax Shepard (Carl), Romany Malco (Oscar), Maura Tierney (Caroline) and Holland Taylor (Rose).