Some sperm donation clinics invite men to leave a message behind for their unborn child to hear when they are 18.
What do they say?
That question inspired The Sperm Monologues, a thought-provoking new play at the Edinburgh Fringe arts festival about the motives behind these video time capsules.
James Farrell, the play's director and co-author, explained the process.
"This is not compulsory and in the UK messages are written rather than recorded on video. Currently this is a more common practice in the United States," he told Reuters.
"We sent e-mails around to our friends asking what they might say in such a situation and that is where we got the idea for the piece."
Although the title echoes Eve Ensler's hit play The Vagina Monologues, Farrell said:
The Vagina Monologues is very much about women's liberation -- this is my body, this is me. The Sperm Monologues are not about men's liberation, but what we want to say is we do have feelings and we want to be noticed."
David Mildon, one of three actors playing the parade of fathers recording their messages, said: "Things are shifting so fast. The Englishman still has his stiff upper lip but wants to show his feelings too."
The play also broaches the thorny issue of anonymity and how new legislation risks discouraging donors in a country where an estimated 1,000 babies are born by sperm donations every year.
From last year, any man wishing to donate sperm has to be prepared to be identified in case any future offspring wants to trace them.
Some donors do it for cash, others just for a laugh or a dare. But the play's protagonists offer a much broader spectrum of motives.
The divorced philosophy lecturer asks in his message "Is it nature or nurture? Come and find me. I am a human being at sea like you, like everyone."
Another donor explains why he was driven to leave something behind: "I am gay so I cannot do it naturally and yes, I know it is a bit weird to come out to your child before it is born."
A third man, coming up to his 30th birthday, had just got a new job when he discovered he had a terminal illness.
"I have six months to live so I wanted to leave a legacy and you are it. My advice -- don't waste a second."