Women who travel to Greece pay about $7600 for a donated egg and an in-vitro fertilisation procedure, a third of the price for similar treatment with a donated egg in Australia.

Many also make the trip because of a ban on receiving anonymously donated eggs in Australia.

Sydney reproductive scientist Denyse Asher, who works exclusively with women who need donor eggs, last year sent about 120 couples and single women to Greece, Spain and South Africa for donations. Most patients are under 50, but one 53-year-old who went to South Africa has just given birth to a baby boy, she said. Fairfax Media also knows of one women in her late 50s who became pregnant.

Comedian Mary Coustas, 49, raised the profile of older women travelling to Greece for egg donation after she gave birth to a daughter, Jamie, in November last year following miscarriages and the stillbirth of another daughter.

But some Australian fertility specialists warn that not knowing the identity of donors could pose ethical and medical problems. In Australia, women must find a donor known to them and pay all medical expenses, but are not allowed to buy eggs. But in Greece, young women are paid €1000 ($1500) to donate and many do it to make extra money.

Ms Asher, who runs the Bondi Junction clinic Donor Eggs Australia, said ''draconian laws'' in Australia meant women often had no option but to travel overseas. In the 13 years she has been sending patients overseas, about 360 babies have been born, she said.

Occupational therapist Suzy Heeks always dreamt of having children, but approaching 40 and in a relationship with a man who did not share the dream, she realised she would need to go it alone.

Ms Heeks used an Australian sperm donor and went through IVF to have her daughter, Abigail, now 5. But she wanted Abigail to have siblings.

After many further rounds of IVF and being told her chances of becoming pregnant with her own eggs were slim, Ms Heeks decided to travel to Greece and use donor eggs from Athens clinic Embryoland. At 44, she fell pregnant with twins Holly and Lachlan, born on Christmas Eve last year.

''I wanted it to be anonymous, I didn't want to be living down the road from my donor,'' she said, adding the ''reasonable costs'' of Greece appealed to her after spending huge amounts on IVF.

Kee Ong, a fertility specialist at Monash IVF, does about 50 donor cycles each year at his Gold Coast clinic. Monash IVF can import eggs from the US-based World Egg Bank at a cost to patients of about $20,000. Some of Dr Ong's patients find their own donors through online forum Egg Donation Australia.

Dr Ong urged women to consider finding a local donor rather than travelling overseas.

In Victoria, a central registry stores identifying information about donors and babies born from donor eggs or sperm.

''We do not encourage the use of overseas donors as they do not satisfy legislative requirements and the most important thing is the unavailability of identifying information of the donor,'' Dr Ong said.