She announced the news on Twitter: "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!"
Kristin, 25, and Jay, 29, initially got engaged in April 2011 but called off their wedding plans three months later. They reconciled shortly afterwards, and Kristin revealed she was pregnant in January.
The couple decided to wait until after the baby's birth to tie the knot.