undreds of healthy unborn babies are being miscarried or stillborn every year in the UK because of the Government-led approach to testing for Down’s syndrome, according to a new study published in Down’s Syndrome Research and Practice.
In 2006, 1,028 abortions were carried out because the unborn child had Down’s syndrome. If this latest research is correct, 400 healthy babies would also have been “lost” that year because of the high-risk tests.
Only about 660 live births of babies with Down’s syndrome in that year would have been prevented by the abortions as the others would have spontaneously aborted or miscarried, the authors claim. Professor Sue Buckley added that she considered the basis of such testing as “unethical”.
However, US scientists believe they may have developed a non-invasive test to detect chromosomal abnormalities in foetuses. The new technique takes advantage of fragments of foetal DNA that are found in maternal blood. The researchers sequenced cell-free DNA randomly from the plasma of 18 pregnant women. They then counted chromosomes by using the fragments of foetal DNA and measuring how many gene fragments originated from each chromosome; for example, women with a Down’s syndrome foetus had more chromosome 21 fragments in their blood than women with normal pregnancies. They successfully identified all nine cases of Down’s syndrome, two cases of Edward syndrome and one case of Patau syndrome. The technique could detect trisomy as early as the 14th week of pregnancy.
The next step, the scientists say, is to repeat their study in a larger number of women. If their technique holds up in further research, they expect that it would be simple and inexpensive to use in clinical settings, especially as other forms of genetic testing become popular.
Stanford university’s Professor Stephen Quake and the study’s senior author expects it would take the next two to three years to reach the clinic, assuming that the larger trial was successful.
