Jennifer Aniston said she made "The Switch," her newest movie, because of what she called its "modern" take on parenthood. She stars with Jason Bateman in this comedy about a single woman who gets artificially inseminated.

"It's happening to so many of my friends," said Aniston, 41. "whether they're going through the pain and agony of fertility treatments or adoption, the waiting and hoping and everything. It's a difficult time."

Single woman Kassie (Aniston) tells her friend Wally (played by Jason Bateman)that she wants to have a baby through artificial insemination. But one drunk night has made Kassie's plans go awry as Wally unwittingly switches someone's semen with his own.

After seven years has passed, Wally finally finds out that Kassie's son carries his blood because the boy has a neurotic problem similar to his own. Now, he is determined to be a good father for his child without telling Kassie the truth, while he also falls for her. Aniston said motherhood has been on her mind for years. She said. "It resonated with me in my 20s and my 30s, and it still does. It's something that always will resonate with me. That's part of my sort of instinct."

In addition to "The Switch," Aniston fans can see their idol in the new "Harper's Bazaar" magazine in which she pays homage to Barbra Streisand by replicating some of Streisand's iconic looks.

"I want to sing like Barbra!" Aniston said, laughing. "The shoot was just fun. Look, you're dressing up in wigs and costumes and going into this beautiful theatre in downtown Los Angeles, and her voice is booming through the speakers. You get chills. It was almost like . . . 'cause at photo shoots I'm always uncomfortable, because that sort of thing is not my career, it's not my profession. So, it was sort of fun to kind of play a character like that."

After dabbling in directing with the 2006 short "Room 10," she's hoping to do more work behind the camera.

"I really am chomping at the bit to do that next," she explained. "It was so creatively fulfilling. And I'm ready to do something else. It's time to sort of explore and I love this (acting). I'll never stop doing this until people say, 'Stop!' And maybe even then I won't stop," she continued, laughing. "But it's just time to sort of change it up."

"The Switch" opens in cinemas stateside 20 August.