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."