In vitro fertilization was used to help Angelina Jolie conceive twins, media reports indicate.
If sources are to be believed, Jolie and partner Brad Pitt turned to fertility treatments to conceive twins Knox and Vivienne.
"They conceived through in vitro fertilization," Usmagazine.com quoted a well-placed source, as saying.
The source further added that 'Tom Raider' star chose the procedure, "as the she wouldn't have to deal with the stress of trying to get pregnant."
Knox and Vivienne were born in Nice, France on July 12. The couple already has three adopted kids Maddox, 6, Pax, 4, Zahara, 3, and a biological daughter Shiloh, 2.