Jan Wilson, 45, (not her real name) placed an advertisement last month and has already had four replies. She said: “I’m elated and very grateful to these women who have come forward. I hope that at least one will prove to be a suitable donor.”

Mrs Wilson, from Yorkshire, gave up her job as a deputy head two years ago to concentrate on infertility treatment after trying unsuccessfully for a baby for 10 years.

“I was a career teacher who became a deputy head quite young and like many successful women, I put off having children. My first marriage broke up and when I married my second husband 10 years ago he was more keen than my previous partner on having a family. Unfortunately, it didn’t happen.”

Eventually, Mrs Wilson and her 45-year-old husband, a computer manager, decided to pay for treatment at the London Gynaecology and Fertility Centre, which pioneered egg donation in this country in 1986.

Professor Ian Craft, the clinic’s director, told the couple their best chance of conceiving was to use eggs from a younger woman and advised them to advertise for a donor. They placed an advert in a national newspaper last year and a teacher came forward, but the treatment did not work.

“It was heart-breaking,” Mrs Wilson said. “We’ve decided to have one more try but then we’ll stop. The treatment is very expensive and if we’re not careful, we could become extremely depressed.”

Mrs Wilson said she was not looking specifically for a teacher to donate eggs, but as one came forward last time she thought she might be lucky again.

“When I was younger I went through a phase of resenting the ease with which other women can have children, but you can’t afford to dwell on these bad feelings. Anyone who donated eggs could rest assured we have thought about having this treatment very, very carefully and would love and treasure any child that came along as a precious gift from someone else,” she added.

There is a severe shortage of egg donors in this country. The waiting list for treatment at Professor Craft’s clinic has been as long as 18 months, which is why he often advises patients to advertise for donors.

A number of organisations have sprung up which can put people in touch with donors - for a fee - but although it is not illegal to buy or sell eggs, the Human Fertilisation and Embryology Authority, which controls fertility treatment, strongly opposes the practice.

Professor Craft said: “Although I don’t agree with paying for eggs, one is desperate to find donors. In a way I feel helpless to help because the problem is so enormous.”

In vitro fertilisation, or IVF, does not come cheap. Each treatment can cost about Pounds 3,500, including the cost of screening and drug therapy for recipient and donor.

If you would like to donate eggs you can contact Nurse Jane at the London Gynaecology and Fertility Centre on 0171 224 0707 quoting reference number 05965.