By Stephen Adams
A team has been able to predict the whole genetic code of a foetus by taking a blood sample from a woman who was 18 weeks pregnant, and a swab of saliva from the father.
They believe that, in time, the test will become widely available, enabling doctors to screen unborn babies for some 3,500 genetic disorders.
At the moment the only genetic disorder routinely tested for on the NHS is Down’s syndrome.
This is a large-scale genetic defect caused by having an extra copy of a bundle of DNA, called a chromosome.
Other such faults are sometimes tested for, but usually only when there is a risk of inheriting them from a parent.