In the mercifully small genre of Hollywood movies adapted from self-help books, “What to Expect When You’re Expecting” ranks roughly in the top third, above “He’s Just Not That Into You” and “Think Like a Man,” below “Mean Girls,” and way below the seminal (sorry) “Everything You Wanted to Know About Sex But Were Afraid To Ask.” The movie’s a canned studio confection — one of those ensemble comedy-dramas with multiple plots and predictable dilemmas, and it’s closer to a greeting card like “Valentine’s Day” than anything else. But the writing is sharp and the performances bright, and if you’ve been through the forced gestational march known as pregnancy, there are knowing laughs to be had. If you haven’t, do yourself a favor and stay away.

The setting is Atlanta — or the Georgia Chamber of Commerce’s version of Atlanta, where every day is blissfully sunny except when the characters are sad and it rains. The story lines represent every variation on having a baby short of cloning. Wendy (Elizabeth Banks), a children’s book author and pregnancy store proprietor, and her husband Gary (Ben Falcone, of “Bridesmaids”) are finally with child after years of trying. Baby photographer Holly (Jennifer Lopez) and Alex (Rodrigo Santoro) are adopting an infant from Ethiopia. Rosie (Anna Kendrick) and Marco (Chace Crawford) are 20-something food truck rivals whose one-night stand lands them in the obstetrics ward. (Don’t worry; Marco is mostly excited to be a dad and the A-word is allowed nowhere near the script.)