UK physicians could soon be allowed to screen embryos for a range of genetic abnormalities. The Human Fertilisation and Embryology Authority (HFEA) agreed in principle on Friday to allow a technique known as aneuploidy screening for the first time in the UK. They said they were in favor of giving licenses to two UK clinics within a strict framework of monitoring and control. But opponents have hit back at the decision claiming it bring the UK a step closer to allowing the creation of the "perfect" designer baby.

The HFEA said the aneuploidy screening could be of particular benefit for women who have suffered repeated miscarriages or IVF failures. It would allow scientists to screen out any embryos that were aneuploid - carrying an abnormal number of chromosomes. This would mean that the remaining embryos were more likely to successfully implant as aneuploid embryos usually result in a failure to implant or a miscarriage.

The clinics seeking approval are in London and in Nottingham. Both clinics have applied to get the licences to operate the screening.

A spokesman for the HFEA said: "The Committee is minded to issue licences, but any such licence would be subject to satisfactory inspection of the intended laboratories; approval of clinic staff; the provision of detailed technical and patient information; and ongoing monitoring. No licence has yet been issued. The Authority recognizes that while the technique has been implemented in a number of clinics around the world, it is still in its early stages. Strict controls and monitoring will be put in place for any licensing of aneuploidy screening, as they currently are for techniques such as pre-implantation, genetic diagnosis (PGD) and intra-cytoplasmic sperm injection (ICSI)."

But Dr Richard Nicholson, editor of the bulletin of medical ethics, said: "It is just one more little step towards the day when parents can chose the "perfect" child and not have anything else."

Dr Nicholson said that although the screening would help improve the success rate for IVF, that it was important to realize that the same technique can be used to screen out other abnormalities like Down's and Turner's syndrome.

Until now fertility specialists in the UK have been allowed to screen only for specific genetic disorders.