I'm pretty sure you are referring to the case of Candace Newmaker. She participated in a therapy called rebirthing, and the therapist specialized in treating children with reactive attachment disorder. The theory was that having a child mimic going through the birth canal would somehow cause them to leave the past behind and attach to the adoptive mom from the beginning. They lay in a fetal position on their side, and the staff presses pillows on them. They then have to push their way out of the "birth canal". It went horribly awry and Candace died.
Perhaps it's not the story you are thinking of because:
"Connell Watkins and her assistant were charged with reckless child abuse resulting in death, and sentenced to 16 years in prison. The other two people who had held the pillows in the video were given 10 years probation for criminally negligent child abuse and sentenced to serve 1,000 hours of community service as part of a plea bargain."
The Story Of The Quack Therapist Who Killed A Child With "Rebirthing" Therapy