The fertility watchdog has approved the extension of embryo screening to allow tests for propensity to breast, ovarian and colon cancer. Patients with gene mutations that are linked to an increased risk of the diseases will be able to ensure that their children do not carry the same faults.

Fertility experts and geneticists welcomed the decision, but pro-lifers said the testing was tantamount to eugenics.

Screening involves a procedure where a cell from a three-day-old embryo created through fertility treatment is taken and tested before being implanted in the womb. Previously it has been used to weed out embryos shown to carry gene mutations linked to serious conditions that occur in early childhood, such as cystic fibrosis and some cancers.

The Human Fertilisation and Embryology Authority yesterday gave the green light for the procedure to be used in testing embryos for the BRCA1 and BRCA2 gene mutations linked to breast and ovarian cancer, as well as the HNPCC gene known to cause colon cancer. Thiswill allow patients to test for diseases that are not certain to occur, are treatable and tend to develop in later life.