Angelina Jolie is pregnant with twins, her partner Brad Pitt has confirmed to friends.

After weeks of silence on the subject, Jolie's rounded belly on the red carpet of the Independent Spirit Awards on Saturday confirmed she was expecting.

Coinciding with Jolie's bump debut, excited dad Pitt has begun telling friends about their impending arrivals, the Mail Online has learned.

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Eating for three: Angelina Jolie debuts her baby bump with partner Brad Pitt at the Independent Spirit Awards on Saturday

The couple are already adoptive parents to Cambodian Maddox, six; Ethiopian Zahara, three; and Vietnamese Pax Thien, four; and have a biological daughter Shiloh Nouvel, 21 months.

In preparation for the birth this summer, Pitt has been rescheduling his work so he has enough time to spend with Jolie and the children.

A friend of the couple tells the Mail Online: "Brad's been very quiet about this pregnancy so far but this was the weekend he decided to let the cat out of the bag. He's telling everybody close to him, because he's having to change around his work schedule to get ready for the birth.

"They're having twins, Angelina is healthy, and he's thrilled that he's going to be a father once again.

"They didn't exactly plan this pregnancy, but they wanted more children and Brad says Angelina was very willing to have them herself."

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Glowing: Angelina shows off her baby bump for the first time on the red carpet of the Independent Spirit Awards

In contrast to the exotic birth of Shiloh in Namibia in 2006, Jolie is expected to undergo a more low-key birth in her native America.

The friend said: "They want to have these children in Los Angeles or New Orleans. I don't think Brad wants to isolate himself and the family again like he did when Shiloh was born.

"But he's also probably not going to take on a major acting role before the birth either, so he can focus on making sure Angelina is happy, healthy and comfortable."

Pitt will have a tough time balancing his work schedule with family life this year - he's signed up to star in five films, as well as produce seven other movies.

Jolie's pregnancy has ended recent reports the couple were planning to adopt another child to add their rapidly expanding brood.

Pitt has previously joked he wants enough children for his own football team.

Before she met Pitt on the set of Mr & Mrs Smith in 2005, Jolie said she thought she would only adopt children, but changed her mind when she was the actor interacting with her eldest son Maddox.

She said: "I believe I'm meant to find my children in the world and not necessarily have them genetically."

Expanding their brood: Brad and Angelina with their four chidren (L-R) Maddox, Shiloh, Zahara and Pax in Venice last autumn