"It was in my heart to have a boy. I thought Spencer really used to want a boy, and then a few months ago we had a conversation where he said, 'Let's just make sure it's healthy. Boy or girl, I don't care,'" Heidi gushed to the magazine at the time.
"I hope to have a little girl one day, but for my first child, I really wanted a son. I'm hoping to God that we don't just have one, but if we do, I wanted a son. I thought it'd be a more natural bond for Spencer since he and his dad are so close."
Prior to the child's due date, the reality TV stars enjoyed a relaxing and romantic babymoon in Hawaii.
Heidi shared updates throughout her pregnancy of her growing baby bump on social media. Four days before Gunner was born, Heidi posted a photo on Instagram of the couple wearing crowns while sitting on a picnic blanket surrounded by their four small dogs.
"Family portrait. Ready for our son!" Heidi captioned the image, adding the following hashtag: "9 months pregnant."
Heidi and Spencer got engaged in May 2007 and wed in April 2009, when Heidi took Spencer's last name.
In addition to The Hills, Heidi and Spencer have also appeared on Celebrity Big Brother in the U.K., Celebrity Wife Swap, Marriage Boot Camp, and I'm a Celebrity... Get Me Out of Here!.