The UK fertility watchdog has approved the extension of embryo gene screening to cover a wider range of diseases.
A report said screening should cover 'susceptibility' genes
IVF clinics will be able to offer tests to couples with a family history of breast cancer, ovarian cancer and a type of colon cancer.
The Human Fertilisation and Embryology Authority (HFEA) had only permitted embryo screening for inherited diseases such as cystic fibrosis.
But disability campaigners fear the possibility of pre-natal selection.
The HFEA issues licences permitting fertility clinics to use the embryo screening technique, called pre-implantation genetic diagnosis (PGD), where a cell from a three-day old embryo is tested.
Ten clinics are currently allowed to use PGD to test for inherited conditions where carrying a faulty gene guarantees the resulting child will have the illness.
The HFEA has already licensed PGD a type of bowel cancer called FAP, and cancer of the retina.
It has also been used to screen for cancers that affect young adults or children.
The HFEA's decision also means PGD can be used to check for the breast and ovarian cancer "susceptibility" genes BRCA1 and BRCA2, and the colon cancer gene HNPCC.
WHERE IS PGD ALLOWED?
BRCA1 and BRCA2 carries have about an 80% risk of developing breast cancer. Carrying the HNPCC means the same degree of risk for colon cancer.
BRCA1 carriers also have a 40% risk of developing ovarian cancer.
The diseases do not affect people until they are in their thirties or forties
The HFEA's decision, made at a public meeting in Belfast, will be reviewed in 2008.
Dame Suzi Leather, Chair of the Human Fertilisation and Embryology Authority, said: "The decision today deals only with serious genetic conditions that we have a single gene test for.
"We would not consider mild conditions - like asthma and eczema - which can be well-managed in medical practice.
"We would not consider conditions like schizophrenia where a number of genes have been identified but there is no single gene that dictates the condition."
However, some have expressed reservations about the idea of extending the use of PGD.
Josephine Quintavalle, director of the group Comment on Reproductive Ethics, said previously: "PGD is currently nothing more than a weapon of destruction, aimed at the ruthless elimination of any embryo which does not conform to eugenic concepts of perfection."
Dr David King, of Human Genetics Alert, said disabled people had told him able-bodied people tended to focus on the negative side of disability, and had very poor judgement about what life was like for a disabled person.
"If that is true we need to err very strongly on the side of caution, and only use PGD for the most serious conditions."
'No easier option'
Clara Mackay, of Breast Cancer Care, said incidence of the condition linked to known genes accounted for just five in 100 cases.
She added: "This means that if an embryo is implanted without the affected gene, the child can still develop the disease and would carry the same lifetime risk as anyone in the general population."
But IVF expert Dr Simon Fishel said families should have the right to prevent health problems in their children by selecting a healthy embryo.
"We are talking about serious disorders here, and where there is major cost too to the NHS for treatment and radical approaches.
"Until there is an easier option for cure, we have got an option here for prevention."
Baroness Ruth Deech, former chair of the HFEA, said controls in the UK were tight, and dismissed fears that a relaxation of the regulations would be the start of a slippery slope towards selection of embryos on social factors.
She added: "Nothing is going to be forced on anybody, but for a tiny handful who feel that they would find this burden insupportable I feel that they should be allowed to do what their instincts tell them would be best for their children."