The public is to be asked if embryo screening should be extended to check for faulty genes which are not guaranteed to cause disease.
Embryos could be tested for a wider selection of genes
Embryos are now screened for inherited diseases such as cystic fibrosis.
But the Human Fertilisation and Embryology Authority is asking if embryos should also be checked for genes linked to cancer and Alzheimer's.
Carrying these genes does not mean a person will definitely develop disease, but puts them at an increased risk.
The HFEA issues licences permitting fertility clinics to use the embryo screening technique, called pre-implantation genetic diagnosis (PGD).
Ten clinics are currently allowed to use PGD to test for inherited conditions.
In the future it is possible that women who carry high risk breast cancer genes like BRCA1 and BRCA2 and have a family history of the disease could opt to have fertility treatment using PGD just to screen out these genes - even if they were able to conceive naturally.
The HFEA is asking for views to inform its response to such applications.
Balance of opinion
A discussion document published by the HFEA looks at the ethical questions over whether it is right to test embryos for these conditions in order to avoid passing on a condition that a person might not develop.
Suzi Leather, chair of the HFEA, said: "We would like people to understand the possible uses of embryo testing techniques - both now and in the future - and to hear their views on testing for serious diseases that people have a lower chance of getting or that occur later on in life.
"Looking ahead, we may be asked to consider applications for these kinds of diseases in the near future and will therefore need to make choices about the types of conditions PGD can be used for.
"We would like to hear the views of anyone who might be affected by these choices: from patients, carers and affected families to doctors and staff in treatment centres to parliamentarians, academics and the wider public.
"This way we can begin to balance the views and interests of all groups and move towards building a consensus."
Dr Gillian Lockwood, who chairs the ethics committee of the British Fertility Society, said: "Genetic disease is increasingly the principal cause of premature death in the developed world.
"The embryo screening technique of PGD would allow potential parents who know that they carry damaging genes to realise every parents' ambition to have healthy children."
Dr Ainsley Newson, a medical ethicist at Imperial College London, said: "For couples at risk of passing on a genetic condition, PGD offers a real alternative to terminating a wanted pregnancy.
"Questions about seriousness will always arise, but if we wouldn't wish these diseases on anyone then why shouldn't we let couples avoid this happening to their own children?"
She added: "We must also listen to those living with genetic disease.
"Having children who won't face the same problems can bring huge relief."
But some expressed reservations about the idea of extending the use of PGD.
Josephine Quintavalle of the group Comment on Reproductive Ethics, said: "This is moving towards eugenics.
"It's all about making endless decisions about who is better off dead."
She said, with the breast cancer genes, it could be a 50/50 chance of developing the condition.
But she added: "What we don't know is why some people develop it and others don't - and that's the information we need."
Matthew O'Gorman, of the pro-life charity Life, said the public consultation' on pre-implantation genetic diagnosis (PGD) was "ridiculous".
He added: "The powers of the HFEA should be curtailed. They should inspect clinics and make sure the law is being adhered to.
"A separate bioethics committee should be established as a tough watchdog that will be truly representative."
A public meeting will also be held in London on December 12 where the issue of extending PGD can be debated.