"Baby Mama": What to expect when the surrogate is expecting

"Knocked Up," "Juno," "Baby Mama" ... the uterus, it appears, is the current Hot Thing in big-screen comedy. And it's used to fine effect in the new Tina Fey vehicle, about a single career woman so desperate to have a baby that she'll do whatever it takes — including disrupting her life with the presence of a surly surrogate in her spotless Philadelphia apartment.

Written and directed by Michael McCullers (with script input from Fey and co-star Amy Poehler), it touches on issues familiar to many women, here told for welcome laughs. "I just don't like your uterus," a doctor tells Kate Holbrook (Fey), before informing her that her chances of getting pregnant are "one in a million."

But 37-year-old Kate, an executive for a Whole Foods-like supermarket chain, has mad baby fever, and she's not the sort to give up easily. Signing on with a posh agency, owned by a beamingly fertile Sigourney Weaver, she's soon matched up with Angie (Poehler), who "discontinued" high school and loves Dr Pepper and video karaoke. Soon Kate's eggs (in a funny, music-video-ish sequence) are ensconced in Angie, and Angie — having dumped her common-law husband (Dax Shepard) — is ensconced at Kate's place, complaining about the organic food and enduring Lamaze classes. (The options, intones a breathy birth instructor, are natural childbirth or "toxic Western medication to drug your baby for your own selfish comfort.")

You can see precisely where Kate and Angie's story is going, and "Baby Mama" seems to lose its nerve midway through; McCullers too often lets the movie slip into conventional romantic comedy (Kate meets up with a sweet single dad, played by Greg Kinnear) and backs away from the screamingly funny satire of the fertility industry that the movie could be. But Fey, carrying a feature film for the first time, gives Kate a polished likability and a nicely wry, self-knowing quality. And she and Poehler — whose fox-eyed Angie seems constantly on the verge of shrieky desperation that she never quite gives in to — pop and spark off each other like the "Saturday Night Live" sketch-comedy veterans they are.

A terrific supporting cast keeps "Baby Mama" lively. Steve Martin is Kate's pony-tailed boss, a man who sits cross-legged on the conference-room table during meetings and begins sentences with, "I was swimming this morning with the dolphins of Costa Rica ... "; the performance is a deceptively casual, sly comic gem. Weaver, smiling as if she's just inhaled angel helium, earnestly explains to Kate the rationale behind her high-end surrogacy business: "We don't do our own taxes, do we? We outsource."

And Romany Malco ("The 40-Year-Old Virgin") steals the movie in a few scenes as Kate's friendly doorman Oscar. Hanging out with Angie at Kate's place on a break, Oscar sneaks a peek at the lurid DVD Angie's watching, titled "Extreme Vaginal Delivery." "DAMN!" he explodes, ready to bolt for the hills. "Baby Mama" ultimately gives in to sweetness, but it has some deliciously tart moments along the way.

Moira Macdonald: 206-464-2725 or mmacdonald@seattletimes.com