The killer, identified only as Jelica S, 23, went into labour when she was seven months pregnant.
Using advice she gleaned from the internet she got into the bath at her home in Lucerne, Switzerland, and delivered the first baby on her own.
Jelica S, 23, went into labor with twins when she was seven months pregnant but killed her first son.
But then after the first boy was born she went down to the basement of her home and smashed him against the wall before throwing him to the ground.
She then wrapped him up in a Mickey Mouse t-shirt before putting him inside a giant pink teddy. He suffered multiple skull fractures and a traumatic brain injury.
The horrific scene was only uncovered when Jelica collapsed and lost consciousness from the blood loss.
Explaining her actions she said: ‘I just put him there. I do not know what went on in my head.’ The second boy didn’t arrive for another 31 hours, but he was said to be stillborn.
Jelica wrapped his body up in a towel and hid it in the laundry basket in her kitchen. She has been jailed for a year after a judge heard that she had been suffering from depression.
A court heard that had she gone to hospital after the birth of the first twin the second one could have survived.
She was found guilty of killing her son while the other died as a result of negligence.
They said: ‘She seems naive. In truth, she is tough and calculating.
A psychiatrist said that Jelica was not entirely responsible and that she had suffered with depression for a long time.
The babies were delivered in December 2015 when Jelica was just 20.
She had split up with the baby’s dad only recently and said: ‘He wanted me to abort, then he left me. I was alone