Hollywood stars Kristen Bell and Dax Shepard are expecting their first child.

A representative for the Parenthood actor and House of Lies actress confirmed the news to People magazine.

"They're so excited - they're both ecstatic," a friend told the magazine. "They can't wait to become parents."

"Kristen had a little bit of morning sickness early on but she just started shooting the second season of House of Lies and is feeling great now."

Bell, 32, and Shepard, 37, who began dating in 2007, have been engaged for nearly three years.

Earlier this year they revealed the reason behind their long engagement during a promotional appearance for their film Hit and Run on The View chat.

"The reason we're not rushing to get married is because I don't feel appropriate taking advantage of a right that's denied to my [gay and lesbian] friends." Shepard said.

Bell added: "That's why we've been so hesitant. Dax and I have talked about it a lot, and this issue is very important to both of us. We're just standing up for what we believe in."

In August Bell admitted to Larry King that she was not very traditional and having kids before getting married "doesn't really bother" her.

According to reports, the couple will welcome their newborn in the late spring of 2013.