Pamela Reno, 38, a cocktail waitress, is hoping to use sperm taken from her 19-year-old son, who killed himself while playing Russian roulette, to fertilise an egg from a donor to create an embryo which she would then carry herself.
Ms Reno, who is a single mother, said: "It is the only way I can be a grandma."
The sperm was taken from her son, Jeremy, at Ms Reno's request while he was on a life support system at a hospital in Reno, Nevada. Dr Russell Foulk, who helped to remove the sperm, said it would not be used until ethical and legal issues had been resolved.
"We are in new ground here. We have not had the ability to do this until recently. It's a request that is becoming more and more frequent among transplant physicians," said Dr Foulk. The ramifications of using the sperm to fertilise an egg would be discussed by the hospital's ethics committee.
Dr Foulk, a specialist at the Northern Nevada Fertility Centre, said he would also discuss the implications with Ms Reno. "Ideally you want to find out the intent, who owns the sperm and what the plans are to do with it," he said.
Ms Reno said she was planning already how to raise the grandchild. "I'm going to have Jeremy's picture up on the wall and I'm going to tell the child `that's Daddy'," she said.
A spokesman for the UK Human Fertilisation and Embryology Authority said Ms Reno's request would be unlikely to be granted in Britain even though a woman has given birth to her own grandchild here.
Edith Jones carried an embryo created from an egg from her daughter who was born with intact ovaries but without a womb, and sperm from her daughters' husband. She gave birth to her grandchild, Caitlin Langston, in December 1996.
Ms Reno's case is different because it depended on removing sperm from her son while he was unconscious but on a life support machine.
British law requires that doctors must have prior written consent from a man before they are permitted to remove sperm from him, and the consent must specify exactly for what the sperm is to be used - in the Reno's case, to allow his mother to carry his child.
The law was tightened in the UK following the Diane Blood case in which sperm was removed from Mrs Blood's husband as he lay in a coma without his written consent.
The spokesman said: "In addition to explicit legal consent, fertility clinics would be required to bear in mind the welfare of the child before providing IVF treatment, taking into account its need for a father and the effect on any siblings. "It couldn't happen here."
There are few federal laws governing fertility treatment in the US and in many states there are only voluntary regulations led by local doctors. "Most states are pretty lax," said the spokesman.