Movie Review

★½

BRIDGET JONES’S BABY

Directed by Sharon Maguire. Written by Helen Fielding, Emma Thompson, Dan Mazer. Starring Renee Zellweger, Colin Firth, Patrick Dempsey, Thompson. At Boston Common, Fenway, suburbs. 123 minutes. R (language, sex references, some nudity)

Whatever the many, many faults of “Bridget Jones’s Baby,’’ Renee Zellweger is not among them. The actress has been away from the screen for six years and lately has been the subject of horrible public comments about her looks. This says more about the “problem’’ of being a woman over 40 in the entertainment industry than anything Zellweger does in the movie itself. She’s a trouper, and here she works overtime to squeeze a mimosa out of a lemon. But “Baby’’ is to Helen Fielding’s original 1996 novel and its 2001 movie adaptation what “Sex and the City 2’’ was to the HBO series — a cause not for celebration but overdue burial.

It has been 12 years since the last Bridget Jones film (“Bridget Jones: The Edge of Reason’’), and our heroine is still a “singleton’’ obsessed with “getting down to my perfect weight.’’ Bridget’s turning 43 — “have I passed my sell-by date?’’ she muses — and her co-workers at her London news channel wheel out a cake with a small brushfire atop it. Her friends bail on nights out to stay in with their kids. “Thank God for the gays!’’ says Bridget as she heads to the clubs with her friend Tom (James Callis), who’s about to adopt his own “gayby.’’ I’m using as many quotes as I can for a reason; they’re the rhetorical equivalent of rubber gloves.

Hugh Grant’s character is putatively dead in a plane crash — lucky man — and Bridget’s eternal love, the emotionally constipated Mark Darcy (Colin Firth), is married. No, wait, he’s getting a divorce, and he and Bridget share an impulsive roll in the hay shortly after she has done the same with a mystery man at a pop festival. Discovering she’s pregnant, she faces a dilemma: Who’s the father, Darcy or — wait for it — Internet dating billionaire Jack Qwant, played by Patrick Dempsey. Yes, McDreamy, from “Grey’s Anatomy.’’ You can hear the gears in the target audience’s brains freeze up from the profound philosophical quandary put forth here.

Does that target audience still actually exist? Who knows, but “Bridget Jones’s Baby’’ panders to it shamelessly. There’s a perfectly smart, tart, self-aware comedy to be made about a single woman in her 40s opting for motherhood. This isn’t it. The script is by novelist Fielding, Dan Mazer, and — surprise — Emma Thompson, who gets the film’s sharpest laughs as Bridget’s nonplussed obstetrician. For all that, the dialogue is made up of groaners (“Hashtag: Let’s do this!’’) and easy digs at twentysomething hipsters (“I hate them with all their apps and ironic beards!’’). Behind it all is a bone-deep terror at being older and alone that the film does its level best to leave unexamined.

Zellweger does what she can, narrating Bridget’s chirpy, shallow observations with charm instead of smarm. She sticks the slapstick landings. She almost convinces us that the heroine would avoid an amniotic needle rather than get a DNA test that would end the film after 30 minutes and put us all out of our misery.

And for this, she will probably continue to be mocked. If “Bridget Jones’s Baby’’ is the best an actress like Zellweger can expect from the film industry, maybe she’d be better off just saying “Hashtag: Let’s not.’’

*1/2

BRIDGET JONES’S BABY

Directed by Sharon Maguire. Written by Helen Fielding, Emma Thompson, Dan Mazer. Starring Renee Zellweger, Colin Firth, Patrick Dempsey, Emma Thompson. At Boston Common, Fenway, suburbs. 123 minutes. R (language, sex references, some nudity)

Ty Burr can be reached at tburr@globe.com. Follow him on Twitter @tyburr.