When Nikolas Evans was assaulted in a fight last year outside a bar in Austin, Texas, his mother's dreams for her 21-year-old son -- a college student with "a good head on his shoulders" -- evaporated.
Returning from a night of drinking, Nikolas and a friend were attacked on their way to catch a bus ride home. The fatal blow came when the slight son she called "Pea" was violently knocked sideways by an assailant and struck his temple on the ground.
Nikolas, initially left in the middle of the road, died 10 days later of a subdural hematoma.
"His brain never stopped swelling," said his mother, 43-year-old Missy Evans of Bedford, Texas. "I sat at a picnic table and bawled for an hour. I never cried so hard. I talk to him four times a day and see him twice a week and now nothing. I couldn't lose him. It was too important."
But now his mother is hoping for a legacy -- a grandchild culled from her son's sperm after his death on April 5, 2009. She has heard from hundreds of women who have offered to be egg donors or surrogate mothers for her future grandchild.
Advances in the fertility industry have allowed wives, fiances, girlfriends and even parents to seek post-mortem sperm retrieval when a man dies unexpectedly.
The first report of post-mortem sperm retrieval was in 1980 involving the case of a 30-year-old man who became brain dead after a car accident, according the journal "Human Reproduction."
A birth was first reported in 1999, but since then more than 1,000 such requests are made each year. Most do not result in pregnancy attempts.
"Often parents change their minds," said Dr. Daniel Williams, assistant professor of urology at University of Wisconsin-Madison.
In post-mortem sperm retrieval, sperm is surgically removed from the testes, epididymus and vas deferens then preserved in nitrogen vapor.
Frozen, it can be kept indefinitely, with "no obvious risk to offspring," according to Williams.
The science is easy, say medical experts, but the ethics are not so clear.
"It's an area that is steeped in ethical issues, emotional issues and financial issues," he told ABCNews.com. "These issues can become very challenging because there are no guidelines or laws or rules on how to handle the requests. Often they are handled on a case-by-case basis."
Many doctors suggest that parents like Evans, who are still grieving for a lost child, should have a "quarantine period" as they heal to consider all the ramifications of having a baby from sperm retrieval, including the welfare of the unborn child.
Ethicists worry that the deceased is fathering a child without consent and few younger men have living wills that would address the issue.
Large medical centers like Cornell University recommend that a panel of experts look at all aspects of the retrieval request before parents are allowed to take the next step.
Evans, who runs her own Web development company, said she was barraged with vitriol after she decided to retrieve and freeze Nikolas' sperm. Critics lambasted her for being unmarried, for her lack of formal religion and even accused her of trying to "find a replacement" for her son.
Some wondered how well the child will deal with a father who is dead and a biological mother who is anonymous.