The Switch (2010)

JENNIFER ANISTON and JASON BATEMAN star in The Switch, an offbeat comedy about Kassie, a smart, fun-loving single woman who, despite her slightly neurotic best friend Wally’s objections, decides it's time to have a baby-even if it means doing it by herself... with a little help from a charming sperm donor (PATRICK WILSON). But, unbeknownst to her, Kassie's plans go awry because of a last-minute switch that isn't discovered until seven years later when Wally finally gets acquainted with Kassie’s precocious-though slightly neurotic-son.