‘James’, ‘Kyle’, Adam and Tyree are sperm donors who advertise themselves on unregulated online donor exchanges. They are some of the more prolific donors on the scene - they have at least one hundred between them, but some of them likely have many more.

They say they are driven to help women create babies through a sense of altruism - giving the gift of life. But after their first few donor-babies were born, these men began to optimise their bodies and their methods of donation to be a product that gives results every time they are asked to help. It’s a hobby that can take over a man’s life.

But why, when they are supposed to be “known”, are prolific donors less likely to meet their donor offspring? At what point do the children that prolific donors help create become a photo that can be used to advertise for the next recipient who comes along? When do these kids become another line in a spreadsheet in a game of numbers donors play one another?

In this episode, Dr Aleks Krotoski speaks with these men to understand the motivations of prolific donors, and to try to get to the bottom of where they think other donors’ bad behaviour comes from.