Eighteen-year-old Hannah Mongie had only been dating her boyfriend Kaden Whitney for a couple of months when the two found out they were going to have a baby.

hey both agreed marriage was off the table, given their short time together. The Utah couple also weren't sure they were ready to be parents. "We went back and forward, but eventually Kaden said that we needed to do what was best for the baby and in our case we felt like that was adoption," Mongie said. "When we came to that decision together we felt an immense amount of peace about it." That's when tragedy struck.

Mongie was still pregnant when she received a life-changing call from Whitney's mom. He'd passed away in his sleep. Mongie says she couldn't get out of bed for weeks, completely devastated by the loss -- but in time, she eventually followed through with their decision to put their baby up for adoption.

When little Taggert was born, Mongie got to spend 48 hours with him before handing him over to his adoptive parents, Emily and Brad Marsh, whom she'd met through an adoption website. Before saying goodbye to him in March 2016, she made a video explaining how much she loved him.

Watch Mongie's emotional message to her son below.

She told him the story of how she met his dad and how hard it was when she lost him. She explained through tears how she knew Taggart was meant to be with someone else, and how she found the perfect mom and dad for him in the Marshes.

After making the video, Mongie gave her son to his new parents -- but it wasn't goodbye forever. Through their open adoption agreement, she is still very much a part of Taggart's life, regularly babysitting and spending time with the little boy. One day, he'll watch the video and understand the incredible sacrifice his mother made to make sure he has the best life possible.