The video showed Michael and Martha opening the jewellery box - but not before Martha had some last-minute nerves.
The sweet video also included recordings of friends' and family's voices sharing if they thought the baby would be a boy.
After some hesitation, Martha who is currently eight months pregnant opened the box to reveal a blue ring.
"It's a boy," Michael shouted, as Martha said, "Oh my god, it's a boy."
Fans and friends rushed to the comments to congratulate the couple, who are expected to give birth in March.
The couple have been open with fans about the realities of Martha's pregnancy, documenting both the physical and mental toll of the last eight months.
Last month, Martha shared a lengthy Instagram caption making a candid admission about her pregnancy and how she didn't know how she could be "so up and down."
“I felt OK yesterday but today I literally feel like I’m dying,” she explained.
“Last week I spent 4 days straight in the house on the couch … I have a sore throat, no energy AT ALL. I’m hot and cold. Don’t want to get out of bed.
“I forced myself to get up and go get food just for some momentum, but I couldn’t even get myself out of the car once we arrived.”