sperm

US scientists have, for the first time, made early-stage human embryos by manipulating DNA taken from people's skin cells and then fertilising it with sperm.

Reproduction used to be a simple story of man's sperm meets woman's egg.

These were fertilised with sperm and some progressed onto the early stages of embryos development.

This technology is part of a growing field aiming to make sperm and eggs outside of the body, known as in vitro gametogenesis.

It could help older women who are no longer have viable eggs, men who don't produce enough sperm or people whose cancer treatment has left them infertile.