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Chrissy Teigen asked her husband John Legend to help her document the devastating loss of their stillborn son.

The model and TV personality delivered a stillborn son the couple named Jack in late September, after she suffered heavy uterine bleeding.

Chrissy and John broke the news of the family tragedy to fans online with a series of black-and-white shots of the stars mourning their third child in the hospital.

Photo may have been deleted

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Now Chrissy is pouring her heart out about the medical cause of her loss in an emotional open letter for Medium.com.

Chrissy reveals she was diagnosed with partial placenta abruption, which caused her heavy bleeding, and the moment doctors confirmed their son would not survive.

"After a couple nights at the hospital, my doctor told me exactly what I knew was coming - it was time to say goodbye," she writes. "He just wouldn't survive this, and if it went on any longer, I might not either."

"I was told it would be time to let go in the morning. I cried a little at first, then went into full blown convulsions of snot and tears, my breath not able to catch up with my own incredibly deep sadness.

"Even as I write this now, I can feel the pain all over again. Oxygen was placed over my nose and mouth, and that was the first picture you saw," she explained, referring to the images she shared on Instagram.

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Chrissy, 34, seen in public for the first time since losing her baby, was criticized for taking photographs of her tragic loss. She explained why she felt it necessary to photograph such personal heartbreak - even though it was clear John was dead set against it.

"It didn't make sense to him at the time," she explains, "but I knew I needed to know of this moment forever..."

Addressing her critics, she declared:

"I cannot express how little I care that you hate the photos. How little I care that it's something you wouldn't have done. I lived it, I chose to do it, and more than anything, these photos aren't for anyone but the people who have lived this or are curious enough to wonder what something like this is like. These photos are only for the people who need them. The thoughts of others do not matter to me."

Chrissy was thankful for all the messages of condolence from fans and friends, some of whom have experienced similar tragedies. She assured followers she read every single message.

"Thank you so much to every single person who has had us in their thoughts or gone as far as to send us your love and stories," she adds. "We are so incredibly lucky."