Liam Hardy was found unconscious at the home in Sutton, London, last Tuesday. He was taken to the St George's Hospital in Tooting but died eight days later.
It is believed he was the latest victim of the 'fainting game' in which young people choke themselves to achieve a brief high.
Liam's girlfriend Paige Ramsay is pregnant with their daughter.
She has left a number of messages on a Facebook page which was set up in the teenager's memory.
In one she said: "Not long until our baby girl is here Liam. I can't wait to meet her so then I'm finally holding part of you again.
"I know I always said I was scared of giving birth but now I just don't care because then you'll finally be looking back at me again."
A memorial has been set up in tribute to Liam in front of Carshalton Boys' Sports College which is covered in flowers and messages.
The 'fainting game' is a craze which started in America and campaign groups say 86 people may have died in Britain as a result of the game.
An inquest into the teenager's death has been opened and adjourned and the Metropolitan Police are not treating the death as suspicious.
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