Britain’s fertility watchdog decided on Wednesday to extend genetic screening of human embryos used in IVF treatments to check for faulty genes that increase the risk of breast, ovarian and bowel cancers.

The Human Fertilisation and Embryology Authority (HFEA) had previously only allowed a technique known as pre-implantation genetic diagnosis (PGD) for inherited diseases such as cystic fibrosis and two cancers that affect young adults and children.

“The authority agreed that we should consider the use of PGD embryo testing for conditions such as inherited breast, ovarian and bowel cancers,” said HFEA chair Suzi Leather.

“These conditions differ from those already licensed before because people at risk do not always develop cancer, it may occur later in life and some treatments may be available,” she added in a statement.

But Leather said the decision does not open the door for wholesale genetic testing, as some critics have suggested. The circumstances of each case will be carefully assessed, she added.

It means families with the inherited cancers can have embryos screened before transfer to the woman’s womb to ensure they do not carry faulty genes that would predispose them to the illnesses.

Mutations in the BRCA1 and BRCA2 genes result in about an 80 percent risk of breast cancer while another faulty gene carries similar odds for a type of colon cancer. BRCA1 carriers have a 40 percent risk of suffering from ovarian cancer.

Leather said the decision deals with serious genetic conditions for which there is a single test. The HFEA would not consider genetic screening for mild conditions like asthma or eczema or schizophrenia where a number of genes have been identified.

The HFEA had previously approved genetic screening for an inherited type of eye and bowel cancer that conveyed a 90 percent increased risk.

Fertility doctors praised Wednesday’s move.

“The decision to use PGD to screen for cancer genes is welcome,” said Professor Robert Winston, a leading fertility expert.

Professor Peter Braude, chairman of the Royal College of Obstetricians and Gynaecologists Scientific Advisory Committee, agreed.

“Cancer is a serious condition. Any opportunity to prevent or reduce its occurrence is a key component of good preventive medicine,” he said. “I am delighted that the HFEA have made a decision that is in the interests of patients at risk.”