BREAKING NEWS: Sarah Jessica Parker, Matthew Broderick Expecting Twin Girls!

See photos of other stars who have twins!

The couple's reps said they are expecting the birth of twin daughters this summer through a surrogate pregnancy, the Associated Press reports.

The Sex and the City star and her actor husband are "overjoyed," their publicists said Tuesday.

The couple already has a son, James Wilkie, 6.

On Monday evening, Parker and Broderick attended the premiere of his film, Wonderful World, at the Tribeca Film Festival in NYC. Parker, who held hands with her husband as they watched the movie, said she was "very happy" to be with him.

Check out adorable photos of babies born last year.

"I'm always thrilled to accompany my husband -- pretty much at any event!" Parker said.

Broderick also told Usmagazine.com that he was thrilled to have her by his side.

"I'm happy that she came out," he told Us before the two laughed at each other.

Find out what other TV stars are pregnant!

Parker, who said last May that she feels more comfortable in the role of mother than any other on-screen part, insists on being a hands-on parent.

"I put him to bed every night -- I get him dressed," she said of her son. "I'm the one who gives him his toothbrush. I take him to school every morning. He's very small, but his personality is 6 foot 4."

Parker will soon star in the highly anticipated sequel to Sex and the City, which is slated to for release in May 2010.