Baby Mama

If we cannot agree that Tina Fey and Amy Poehler are two of the funniest women in television, then we have nothing to say to each other. But I know there are people who hate them, who think they ruined “Saturday Night Live,” who automatically despise any sketch in which Poehler (who’s still on the show) appears, and who refuse to watch “30 Rock” (which Fey created and stars in). I am puzzled by these people, but hey, to each his own.

The haters won’t bother seeing “Baby Mama,” of course, nor should they. Directed and written by former “SNL” scribe Michael McCullers, with uncredited script touch-ups by the ladies themselves, the film is so purely a Tina ‘n’ Amy product that you’d swear no one else was even involved. Fey’s character, a 37-year-old businesswoman, is not appreciably different from Liz Lemon, Fey’s “30 Rock” single gal. And Poehler’s belligerent white-trash character is the spitting image of Amber, the flatulent one-legged skank she’s played in several “SNL” sketches.

In “Baby Mama,” Fey plays Kate, vice president of development for a chain of health-food supermarkets, and a happy, fulfilled career woman. (Her boss is a ponytailed New Age hippie played by an unbilled Steve Martin.) The only problem? She really, really wants to have a baby. Her ovaries tingle whenever she sees one. She has no boyfriend or husband, however, and even if she did, her T-shaped uterus makes conception unlikely.

The idea of hiring a surrogate to carry her baby is off-putting at first (“It’s weird; it’s for weirdos” is her frank assessment), but finally she consults with a surrogate-matching agency run by one Chaffee Bicknell (Sigourney Weaver). Chaffee sets Kate up with Angie (Poehler), an irresponsible ignoramus who comes complete with a deadbeat common-law husband (“He never asked me to be his wife, but he never asked me NOT to be his wife, either”) named Carl (Dax Shepard). Angie is eager to carry one of Kate’s anonymous-donor-fertilized eggs, and she and Carl are both eager to cash the large checks that are involved in the arrangement.

After a fight with Carl, the newly pregnant Angie moves in with Kate, giving the film the odd-couple dynamic we were expecting in the first place. Poehler and Fey are a remarkably funny pair with years of experience working together, so it’s no surprise that their scenes — Kate trying to get Angie to eat something other than junk food; Angie sticking wads of gum under the coffee table then insisting she doesn’t know who did it — are sharply performed and often hilarious.

Meanwhile, Kate meets a potential new beau, Rob (Greg Kinnear), owner of a fruit-smoothie shop in the neighborhood where Kate’s company plans to build a new store. It’s disappointing that this subplot takes the predictable romantic-comedy turn of having Kate hide Angie’s existence from Rob for fear he’d think it’s weird (why must movie couples always tell such huge lies?), but Greg Kinnear is a welcome presence nonetheless.

Also disappointing is the main plot’s predictability, right down to the moment when Kate and Angie have a big fight in a public place and call each other names. McCullers seems to have structured his screenplay with a template, complete with unnecessary, regularly scheduled plot complications. The better choice would have been to keep things simple and let the humor flow naturally from the basic scenario. The two central characters are strong enough that you don’t need to throw curveballs at them every 10 minutes just to keep the momentum going.

The film is at its best when it satirizes modern upper-class parenting, as when Kate buys a baby stroller with leather upholstery and dual-side airbags, or when we overhear references to children named Wingspan and Banjo, or when Kate and Angie attending a natural-childbirth class and are instructed to rub the expectant mother’s perineum with olive oil. Kate’s baby angst is also a ripe source for comedy, with Chaffee Bicknell’s own remarkable fertility despite her advancing age serving as a nice rub-your-face-in-it running gag. (When she says she’s “expecting,” Angie whispers to Kate, “Expecting what? A Social Security check?”)

I still eagerly await whatever Fey’s screenplay followup to “Mean Girls” turns out to be, and I hope she and Poehler will continue to make films together. Their fine-tuned personas — the barely coping WASP and the madcap trainwreck — complement one another. “Baby Mama” does not represent the best of either woman’s talent, but it’ll do for now.

B (1 hr., 35 min.; PG-13, a little profanity, some vulgarity.)