LONDON Thirty years after doctors delivered the world's first test tube baby, Louise Brown, fertility experts say they must tackle a growing problem of reproductive tourism that puts women and babies at risk.
Cheap flights, open borders and rapid-fire medical advances have in the past few years made it much easier for infertile couples to seek in vitro fertilisation treatments in countries where such procedures cost far less.
The issue, these experts say, is that without an international set of standards to help people choose a safe place to go, too many couples end up taking big risks at clinics that may not have adequate standards.
In some cases, desperate couples may not know where the eggs come from, or a woman comes back pregnant with multiple embryos -- the single biggest risk for mother and child during in vitro fertilisation or IVF, researchers say.
"Governments, patient organisations and doctors should organise awareness campaigns to warn citizens for possible dangers of cross-border care and to inform them of the possibilities," Guido Pennings, an ethicist at Ghent University in Belgium, said at a recent conference.
More than 3.5 million babies have been born worldwide using assisted reproductive technology since July 25, 1978, when University of Cambridge researchers Robert Edwards and Patrick Steptoe delivered Louise Brown by Caesarean -- the world's first test-tube baby.
Most treatments are among women aged between 30 and 39.
But that number is growing even faster these days because more and more women are waiting longer to start having children, and cheaper air travel makes it possible for even more couples to seek IVF.
The treatment involves surgically removing eggs from a woman's ovaries and combining them with sperm in the lab. Doctors then pick the best embryos -- typically one or two -- and implant them in the woman's uterus.
Europe leads the way in the number of procedures, followed by the United States. But other nations are catching up and European fertility experts see a trend of woman returning from treatment in other countries with multiple pregnancies.
This means best practices are not uniform across Europe and safety measures introduced in some countries are restricted or illegal in others. In Italy, for instance, freezing embryos is outlawed, forcing some people to other countries.
An important difference occurs in the rules on the maximum number of embryos that can be transferred to a woman's womb. In Britain and Scandinavia only one or two are allowed, but other countries do not have this restriction, increasing the risk of twins or triplets.
At the same time, higher costs in Western Europe drive many couples to Eastern Europe and beyond where they can receive treatment for far less, experts say.
"Patients sadly often come back with a high rate of multiples from some places of the world where the standards are not as high," said Francoise Shenfield, a fertility expert at University College London who focuses on ethics as a member of the European Society of Human Reproduction and Embryology.
(Reporting by Michael Kahn; Editing by Maggie Fox)