International trafficking of children for adoption has reached unprecedented levels and will continue to rise, an academic study says.
More than 32,000 infants, far more than previously thought, crossed national borders to be adopted by foreign families in 1998. Most came from Russia and China and ended up in North America and western Europe.
The rise in trafficking - 50 per cent over the previous decade - has been fuelled by a growing demand for children by childless couples in rich countries.
Although the practice is not significant compared with immigration, it has raised concerns that proper controls be enforced to ensure the welfare of the children.
The analysis of official data was conducted by Peter Selman, reader in social policy at Newcastle University and chairman of the Network for Intercountry Adoption. It will be published in the journal Population Research and Policy Review .
Dr Selman said: "The scale of intercountry adoption is greater than is usually acknowledged and could potentially grow in the first decades of the next century, making international controls even more important."
Half the children go to the US, which took in 16,396 in 1999. France, Italy, Germany and Canada also take large numbers.
If the annual number of live births in each nation is taken into account, Scandinavian families emerge as the most eager to adopt foreign children.
The flow of children from poor to rich nations has been prompted by childless couples who have not succeeded with infertility treatment and have found fewer opportunities for domestic adoption in recent years.
More than 5,000 Russian children were sent abroad to be adopted in 1998. Almost as many came from China.
When birth rate is factored in, Eastern Europe is the main provider. For every 1,000 births, there are 4.9 adoptions in Bulgaria, 4.4 in Romania and 3.6 in Russia. These countries have economic problems but are not the poorest and do not have high birth rates. Annual deaths in Russia now exceed live births by 50 per cent, but the state cannot afford to keep growing numbers of children in institutions.
China's one-child policy has prompted many couples to send girl babies abroad so they can try again to have a son.
More than 120,000 Korean children have been adopted overseas since 1955, and the stigma of unmarried parenthood has maintained the flow of children despite the country's recent prosperity.
An adoption bill being considered by Parliament would allow the UK to ratify an international treaty designed to police intercountry adoption.
But the practice is rare in Britain. There were 4,800 adoptions in England in 1999-2000, but the Department of Health recorded just 350 applications for overseas adoptions. There are 58,990 children in the care of local authorities in England.
Despite the high profile of Alan and Judith Kilshaw's attempt to adopt US twins over the internet last year, no one is forecasting a rise in overseas adoptions.
Neera Dhingra, spokesperson for the British Association for Adoption and Fostering, said that it was better for adopted children to remain in their own country and that those from abroad would have identity problems if they lost touch with their homeland's culture, language and religion.
Nevertheless, she said: "Overseas adoption can be very beneficial and provide a loving home for children that they would otherwise be denied."