Woody Allen once turned a self-help book into a killer comedy—Everything You Always Wanted to Know About Sex . . . but Were Afraid to Ask—so technically the genre isn’t beneath contempt. But this movie is. Adapted from the perennial best seller by Heidi Murkoff, it intertwines four stale story lines about expectant mothers (Elizabeth Banks, Cameron Diaz, Anna Kendrick, Jennifer Lopez) as it trudges toward the preordained warm glow of an ending. The cast includes Chris Rock, Dennis Quaid, and some of the more affordable faces from Bridesmaids (Ben Falcone, Rebel Wilson, Wendi McLendon-Covey), though the only real pleasure is Banks, a skilled comic player (Role Models, The 40-Year-Old Virgin) who puts the other three women to shame. Kirk Jones (Nanny McPhee) directed a script by Shauna Cross (Whip It) and Heather Hach (Freaky Friday).