I found the whole process fascinating and rewarding, and when Alison contacted me to tell me that the first couple Id donated to hadnt eventually conceived, she also told me she was setting up Altrui, and I got involved. Its an amazing thing to be a part of. I wouldnt donate again, as Im focusing on my own family now, but I love supporting other donors with their journeys.

I told Lyndon about it all not long after we met, but there was never a problem he has two children from a previous relationship so we both come with a past. Having my daughter has just confirmed how precious my eggs must have been to the couples whose lives I have changed. Im sure that when she is able to understand what Ive done she will be proud of her mum.

Alan Fisher 35, is a data analyst and lives in Nottingham with his girlfriend, Cat. He joined the UKs blood cancer charity and bone marrow register, Anthony Nolan (anthonynolan.org), in 2010 and donated bone marrow at the London Clinic in January

It was a memorable drive to work the day I decided to donate. I tuned into the local radio station to hear a six-year-old boy hosting the breakfast show: he had leukaemia and was raising awareness for the Anthony Nolan register. It was amazing to hear a young, confident voice doing such a brave thing, and I pulled into the office car park feeling uplifted. But as I reached down to turn off the engine the show ended, and I heard the usual presenter explaining that it had been a tribute to the boy, who had died because a donor hadnt been found in time. There and then I knew I would sign up.

I went along to a Join for Joel event organised in memory of the boy, Joel Picker Spence. It was easy: all I had to do was give a saliva sample. Knowing I could be called to donate within months, years or never, I didnt think about it much after that.

A year and a half later I was contacted and told there was a potential recipient for my bone marrow, but after more tests it transpired that they didnt need me. It was a bit of an anticlimax, to be honest. But in 2013, just before Christmas, I got another phone call and recognised the number on my phone. Its my turn now, I thought.

My employers were great about me taking time off. The hospital wanted to take bone marrow under general anaesthetic from my pelvic bone. It seems like the more invasive option you can sometimes give by a stem cell blood donation but as I dont like needles I didnt mind the idea of being knocked out.

The procedure itself went fine: I spent the night before at hospital and was taken to theatre early. When I awoke after the operation, which took less than an hour, I actually thought it hadnt happened. I was left feeling drained, but only for a few days. I also had two small puncture wounds in the small of my back, but they healed nicely. For me, it was a minor inconvenience for the recipient and their family, I hope it has meant a lot more. I found out afterwards that the amount of bone marrow needed indicated that the recipient was a child. Before I was discharged, I also found out it was a young boy, about the same age as Joel.

Jay Kelly 36, is a fertility and birth hypnotherapist. She is divorced and lives in Harrogate with her four daughters, aged 13, 10 and seven (twins). She recently gave birth to a baby for another couple, whom she met through Surrogacy UK (surrogacyuk.org)

Deciding to become a surrogate wasnt some road to Damascus moment. It was something that had been bubbling under for a long time. Through my work I meet a lot of women unable to conceive and I just cant imagine how distressing it must be for them. My children are everything to me, and it struck me that if I could help a couple who couldnt have what I have, it would be a pretty amazing thing to do.

See more here:
Would you donate a kidney to someone you had never met?