Reality TV star Kristin Cavallari has given birth to a baby boy.

The former The Hills star and her fiance, American football player Jay Cutler, became first time parents on Wednesday.

Announcing the new arrival on her Twitter blog, she writes, "We are thrilled to welcome Camden Jack Cutler into the world. He was born this morning weighing 7 lbs 9 oz. Everyone is doing great!"

The couple initially became engaged in April, 2011, but called off the wedding plans three months later. Cavallari and Cutler reconciled weeks later and revealed they were expecting a child together in January.