Fertility specialists are pushing for tighter controls to reduce the number of multiple births from IVF treatments, a leading expert said today.
The number of twins and triplets has risen since Louise Brown, the world's first in-vitro fertilisation (IVF) baby, was born nearly three decades ago.
In Europe now, almost a quarter of successful fertility procedures result in multiple births.
Professor Paul Devroey, chairman of the European Society of Human Reproduction and Embryology (ESHRE), believes it is too high and that more needs to be done to reduce the risk.
"There is a need to replace fewer embryos and ESHRE is pushing to do that," he said in an interview before the start of the society's annual meeting.
The number of embryos placed in the womb during IVF varies from one to four depending on the country.
Doctors use more embryos to raise the chances of a pregnancy but it also increases the risk of multiple births, which is dangerous for the mother and children.
Having twins or triplets can lead to complications in the mother and premature birth, low birth weight and physical and developmental problems in the children.
"Fewer and fewer embryos are replaced in countries but still too many are transferred, especially in the high risk group of young women," said Prof Devroey.
He added that transferring one embryo gives almost the same result as two but without the risk of multiple births or the added costs of caring for premature infants.
Experts attending the conference will also present research on improving ways of freezing eggs, stopping IVF identity fraud and screening embryos for an abnormalities such as Down's syndrome.
Nearly 6,000 doctors, researchers and scientists are attending the four-day meeting in the Czech Republic.
More than 2 million babies worldwide have been born as a result of fertility treatment.