Within months, a new non-invasive prenatal test for Down syndrome will be available in Australia. The new test is reportedly ‘risk free’ for the foetus.
Previously, the only method for determining whether a foetus had Down syndrome was through one of two invasive methods of diagnosis: amniocentesis or chorionic villus sampling (CVS). Amniocentesis involves a doctor inserting a large needle into the uterus to get a sample of the amniotic fluid and CVS involves another needle, this time used to gather a sample of placenta tissue.
These methods of testing are usually only performed by six percent of women. Why so few? Well, women rarely undertake the tests unless they fall into an ‘at risk’ category because the tests themselves do cause a risk of miscarriage.
Now that a non-invasive procedure is available, the question that will inevitably arise is whether more women will be offered the test? And if so, will that mean more foetuses with Down syndrome are aborted?
Currently, only a small percentage of couples decide to keep the baby if tests confirm a foetus has Down syndrome.
Only 5.3 per cent of pregnancies where there is a prenatal diagnosis of Down syndrome are continued. This figure comes from a respected Victorian study, the only (now-defunct) research in Australia that followed the link from prenatal diagnosis to live births of babies with Down syndrome.
Released in 2008 and based on figures from 1986 to 2004, the study was co-authored by associate professor Jane Halliday, a public health genetics expert with Melbourne-based Murdoch Children’s Research Institute. “The vast majority, 95 per cent, were terminated,” she says.
It’s similar across the Western world. About 90 per cent of foetuses with a diagnosis of Down syndrome are terminated in New Zealand, about 92 per cent in the US, about 93 per cent in the UK.
The fact that non-invasive testing will make Down syndrome so much easier to detect means, almost certainly, that more foetuses with Down syndrome will be aborted.