Heidi Montag and Spencer Pratt are first-time parents

Heidi Montag is a first-time mother, after welcoming son Gunner Stone into the world on Sunday (01Oct17).

The tot, whose father is Heidi's husband Spencer Pratt, was born at 3.06pm, weighed 6lbs 12oz and measured 19 inches long, according to a representative for the couple.

"Heidi and Spencer are proud parents of a healthy baby boy as of this afternoon," the spokesperson told Us Weekly.

It's believed that the baby arrived early, as Heidi's due date had been thought to be the 19 October.

The outlet also reports that Gunner has blond hair and blue eyes, with Heidi adding to Us Weekly: "We are so blessed to have a beautiful healthy baby boy. It was the hardest and most rewarding experience."

Spencer added: "Officially the most lit day of my life."

The pair have yet to share any pictures of the new arrival on their social media pages.

The former star of reality series The Hills met beau Spencer while filming the hit show and the couple tied the knot in 2009, which was shown on the MTV program.

Speaking previously about the moment she found out she was pregnant, Heidi told Us Weekly: "I felt nauseous and I wanted to know, so I took a pregnancy test. I was so shocked; Spencer wasn’t. He was so sure it would happen right away. He was like, ‘You’re going to get pregnant the first time we try.’”

Spencer, 34, recalled the moment he learnt he was going to be a father to the news outlet, revealing he got up one morning to find his wife “just standing there” with a glow about her.

“I thought she was about to say she made muffins or banana bread,” he joked. “Heidi said, ‘I’m pregnant.’ I was like, ‘Whoa, that’s way more exciting than banana bread!’”