The reality TV stars - who have been married for eight years - revealed last month they are having their first child together, and they were recently delighted to learn they will be welcoming a son into the world later this year.
Heidi, 30, said: "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.'
"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."
And Spencer, 33, is looking forward to passing his sporting skills onto his son.
Heidi told Us Weekly magazine: "He was really excited! He trains jujitsu all the time, so he's excited to have a little grappler. He'll be doing jujitsu and soccer with him."
The former Hills star - who is 17 weeks pregnant - is looking forward to becoming a mother and is particularly excited about seeing her little boy develop a personality and interests of his own.
She said: "I'm really excited for his personality and his little smile. I'm excited to take him to Disneyland and to see if he's into dinosaurs, Mickey Mouse or ballerinas - it can be anything. Maybe he'll be the best dancer!"