The reasons women donate their eggs vary significantly. Some people say they feel a sense of pride knowing they may help other women conceive children. Others say they want to earn a bit of extra cash, since many clinics are willing to pay donors for their eggs.

Charlotte Edwards, BBC Business reporter, explains how the process of egg donation works — and how it differs by country.

Plus: Elaine Chong, an egg donor in the United Kingdom and BBC journalist, discusses how she wanted to help other women of Chinese descent expand their families. And Ebimoboere Ibinabo Dan-Asisahin, an egg donor in Nigeria, discusses the process and physical side effects she experienced.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 0330 12 33 22 6 Presenter: Hannah Gelbart Producers: William Lee Adams and Benita Barden Video Journalist: Tim Hodges Editor: Julia Ross-Roy