By Rachel MacManus
One in six British couples struggles to have a baby.
Alexandra hopes to be able to pay off her debts
Often it is because the woman is not producing her own healthy eggs and one solution is to use eggs donated by someone else.
The problem is the shortage of voluntary donors who are willing to give their eggs for free.
So if someone is prepared to sell their eggs for thousands of pounds, there are plenty of willing buyers.
Alexandra Saunders from High Wycombe has advertised her eggs on the internet. She hopes to make some money to pay off credit card debt.
She says: "I'm 25 and I've got three jobs - one in an office in the day, two in pubs. I work five nights a week, I'm in quite a bit of debt and I just want to get it paid off really."
An article in a magazine gave Alexandra the idea of selling her eggs.
"I was sat in a doctor's waiting room and I read about it in a magazine. It just said 'sell your eggs for thirty grand' or something like that. And I went and put my name down on a couple of websites.
"It was saying about girls coming from Britain and going to America and selling their eggs. It just sounds a good idea - easy money really - and it helps someone out.
"I'm not using them so, if someone else can, it would be good and also clear me out of a hole too," she explained.
Eggs for sale
So why are so many women having to consider paying someone for their eggs?
Egg donation used to be anonymous but, now the rules have been altered, fewer women are coming forward.
A change in the law last year means that, at the age of 18, a child born from donated eggs can be told who their biological mother is.
Lack of anonymity is not the only thing putting off potential donors. Egg collection is a complicated and uncomfortable process, and involves taking a cocktail of hormones.
Laura Witzens is a spokeswoman for the National Gamete Donation Trust. She thinks more women should be willing to donate eggs altruistically.
She said: "I think the donors want to do it because they see the dollar signs. There's a very interesting book, Confessions Of A Serial Egg Donor, and she's donated five times and she regrets it.
"These girls are typically in their 20s, haven't had families of their own, they're in debt and they want to go on to donate."
But Laura thinks young women who are only interested in being paid for donating may put their health at risk.
She explained: "You don't know about the drugs and what effect it will have if you want your own child, and you're not in a position to judge how you will feel if you can't have your own children."
Stephen and Elaine have twins born using donor eggs
Stephen and Elaine Eades are one of the lucky couples who managed to find a voluntary donor. Their twin daughters Millie and Grace were born earlier this year.
Elaine said: "I wanted a family and I needed a family because that instinct is so strong.
"To be told you need a donor - I won't lie - it was extremely hard to accept because I felt I wasn't a complete woman, it wasn't my eggs and it was very hard."
"But initially I thought if I don't go for this and I don't take this chance, I would have had no chance of having children, and that I could not cope with."
Stephen believes voluntary donors are unique people.
"Without them we wouldn't be where we are today. They give you a gift that we would never have been able to have without a donor," he said.
Alexandra is still waiting for a response to her internet advert but she says that, if someone was willing to pay for the privilege, she'd be happy to go through with donation.
She said: "It's just cells. It's not me giving a baby up. So if it can help - and also it would help me - then I'd do it."
Inside Out: Egg Donors was broadcast on BBC 1 West Midlands on Monday 30 October at 1930 GMT.