Many women are heading to Spain after failed fertility treatment in Scotland, with one Glasgow-based clinic sending about 300 patients to a centre in Valencia since 2011, and another Edinburgh-based organisation saying more than 50 of its clients were going abroad every year.
Spanish clinics have more donors because they retain the right to anonymity, whereas in the UK children born as a result can trace their donors after the age of 18.
The Spanish also have shorter waiting lists and tend to have higher success rates.
Most of those going to Spain were in their 40s and some had experienced failed IVF attempts in Scotland and required treatment with eggs donated by younger women, said Dr Marco Gaudoin, medical director of the Glasgow Centre for Reproductive Medicine (GCRM).
Doctors have found that once a woman has turned 35, egg donation has significantly higher success rates than IVF using her own eggs.
The procedure is carried out in Scottish clinics, however there are few egg donors and waiting lists are long.
A leading Spanish consultant is due to speak to prospective patients in Edinburgh next month. Dr Raul Olivares, of Barcelona IVF, has been invited to a one-day meeting organised by Fertility Concerns, a group advising women struggling to get pregnant.
He said: "I'm offering Scottish patients the possibility of discussing what's involved in an egg donation cycle in Spain - all legal, technical and ethical aspects of it. I'm also going to discuss our experience with some state-of-the-art lab procedures."
Dr Olivares said he believed it was wrong for the UK Government to remove anonymity for donors in 2005.
"I think people tend to compare egg and sperm donation to adoption," he said.
"But egg or sperm donation is a generous act in which someone gives one or several cells that allow the patients to be parents.
"I'd consider it similar to a heart or kidney donation. People are too concerned about the rights of the babies and not the rights of the donors, who may not want someone knocking on their door 18 years later to find out who donated the egg or the sperm.
"Donors are not donating to become parents but to help other people reach their dream."
Egg and sperm donors are given a compensation fee, which in Spain varies across regions. In Catalonia, where most donors are students, the fee is about £800. In the UK, the fee was increased from £250 to £750 in 2012.
Fertility Concerns said about 100 people were due to attend the event with Dr Olivares. It said 50 of its clients went abroad every year for IVF, mostly to Spain.
Between 2011 and 2013 the GCRM sent between 125 to 140 patients a year to IVI in Valencia, with about one-third going for repeat cycles.
Dr Gaudoin said there was a nine-month waiting list for egg donation at his clinic.
He said: "If all the women we facilitate to go to Spain stayed in the UK, our waiting time would quadruple. The primary reason people go abroad is because of the lack of UK donors."
The price of egg donation varies across both Spanish and UK private clinics. In Spain it costs £6,000 to £8,000 per cycle, while in the UK it costs about £5,000.
A Scottish Government spokesman said: "There is a shortage of egg donors across the UK and in Scotland. However, we recognise the issue and are working to address it. That is exactly why we have set up an expert group to look at the challenges and set out a way forward for NHS provision of both egg and sperm donation in Scotland."
A spokeswoman for the UK Department of Health added that the number of egg donors was increasing.