Hannah Mongie, 21, was 18 when she fell pregnant unexpectedly with her boyfriend of eight weeks, Kaden Whitney.
She was distraught when Whitney, a church missionary, died in his sleep from natural causes two months later.
The pair had already discussed adoption and after Whitney’s death, Mongie decided to follow through with it as she believed it would be best for her baby.
In the nine-minute clip, filmed after she had given birth, she sobs: “If I didn’t love you I wouldn’t be in the position at all and you wouldn’t have this awesome family.
“I’m going to give you all the kisses I can before I sign you away to Brad and Emily.”
Mongie had 48 hours with her son Taggart before she handed him over to his new parents, Brad and Emily Marsh, as part of an open adoption.
Open adoption is when contact remains between a birth family and adoptive family who share a common link - an adopted child. Unlike the US, open adoption is rare in the UK, however this doesn’t mean that it’s unheard of in the UK.
Speaking in the video, Mongie said: “I love you Taggart Cayden Marsh. My little boy. My son. I love you so much. Love your mummy, Hannah.”
Mongie, who now regularly babysits Taggart, said: “I’ve wanted to be a mum my whole life, it was something I always knew I would do but the timing was so wrong.
“We had only been dating for two months so we knew we couldn’t get married, it was too early in our relationship, even for the sake of a baby.
“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.”
Speaking about the decision to go through adoption, Mongie said: “When we came to the decision together we felt an immense amount of peace about it.
“It completely shattered my world when Kaden’s mum called my mum with the news that he had passed away in his sleep.
“After he died I didn’t get out of bed for weeks. I didn’t open the blinds.
“My parents began to get worried about me, and although they said they’d support me no matter what, they began to speak about our decision to place my baby up for adoption.
“My dad just said what Kaden and me had already talked about, that our baby deserved to wake up in his crib and have both a mum and dad there to love him.
“I was so torn about it for a while but one day I woke up and I just felt this unexplainable peace. I knew I was going to do this. It was what was best for our baby.”
In March 2016, Hannah went into labour two weeks before her due date and welcomed baby Taggart Kaden into the world in Utah Valley Hospital.
The birth mum said the absence of her boyfriend Kaden was particularly raw during those hours spent with her newborn before his adoptive parents took him home.
“For those first 48 hours I had him all to myself. It was magical but at the same time, I knew the clock was ticking until I had to give him away,” she said.
“I kept thinking, ‘How am I going to do this?’ But I never once thought that I wouldn’t.
“It was so difficult because in the front of my mind was Kaden. Tag was the last piece of him that we had left.
“I wanted Tag to know when he is older just how I felt in that moment and to explain to him why I chose adoption.
“A lot of birth mums write letters but I decided to do a video. For months I didn’t show it to anyone. For months after Tag was placed I didn’t even cry.
“When he was about four months old I showed it to my friend and I just broke down completely in his arms.
“I eventually showed the video to Emily and it was a really special moment between us.”
Taggart is now 22-months-old and Mongie is very much a part of his life, thanks to the open adoption agreement between the families.
Mongie regularly babysits for the family and gets to spend time with Taggart and his two brothers Carter, three, and Lucas, one month, at the family’s home.
Mum-of-three Emily, 27, said she will never be able to thank Mongie, or the birth mothers of her other two sons, for the gift they have given her family.
The pre-school teacher said it was extremely important to her and her husband Brad, 29, that their children had a strong relationship with their biological mothers.
Speaking of the video filmed by Mongie in the days after Tag’s birth, Emily said: “It was really sweet. I didn’t know she had filmed that.
“With our oldest son, his mother wrote him a long letter to read in the future, but it was special that Hannah did this in her own way.
“It is so comforting to know that Tag has that to watch and that he will know how loved he always is by Hannah.”
She added: “We really see everything that Hannah has done for us as the greatest gift.”