Study proves accuracy of new Down syndrome test, increases fears of ‘weeding out’ Down’s children
March 14, 2011 (LifeSiteNews.com) – A recent study published in the journal Nature Medicine and authored by researchers in Cyprus, shows the success of a new prenatal blood test that could potentially replace current invasive procedures used to test for Down syndrome.
But while the testing appears both successful and risk-free, some are warning that such easily available testing may exacerbate the already prevalent practice of “weeding out” children with birth abnormalities.
One Canadian, Dr. Kerry Bowman, a bioethicist at the University of Toronto Joint Centre for Bioethics and at Mount Sinai Hospital, told CTV News that the potential testing raises ethical issues. “You’re decreasing the risks to the unborn child with this less-invasive test, so that’s an advancement. The concern for me would be that people would get the information more quickly and make decisions that aren’t fully thought through,” he said.
The new test takes blood from the mother and compares differences in the mother and unborn child’s DNA. Performed on 40 women, the test accurately diagnosed 14 carrying a child with Down syndrome and 26 “normal” pregnancies.
“The test is the first worldwide to demonstrate 100 per cent sensitivity and 100 per cent specificity in all normal and Down’s syndrome pregnancies examined,” said study author Philippos Patsalis, medical director of the Cyprus Institute of Neurology and Genetics. It is “very exciting,” he said.
The DNA test would replace the current invasive amniocentesis test, which involves removing amniotic fluid from the uterus with a needle. Amniocentesis is typically done during the second trimester, at 15-16 weeks gestation. It carries a risk, estimated at 1-2 percent, of miscarriage. New DNA testing could be done as early as 11-13 weeks gestation and avoid the invasive amniocentesis.
While Down syndrome affects approximately 1 in 700 children born worldwide, according to well-known pediatric geneticist researcher Dr. Brian Skotko, rates should have statistically increased in recent years due to the fact that more women are waiting longer to have children. However, this has not proved to be the case, almost certainly due to the extremely high abortion rate for children diagnosed in utero with the condition.
According to Skotko, in the U.S. between 1989 and 2005, Down syndrome births should have increased by 34 percent. In reality, 15 percent fewer Down’s babies were born, a 49 percentage point decrease from expected numbers.
Dr. Skotko cites international meta-analysis data that indicates 92 percent of women diagnosed with a child having Down syndrome choose to abort their unborn child. He believes the numbers will only increase with easier, quicker prenatal testing.
For his part, Dr. Bowman told CTV that he worried that less risky tests, such as the new DNA one, could lead to an attempt to “weed out” Down syndrome and other birth abnormalities. “And is Down syndrome truly an abnormality that needs to be stopped, or is it just a variation of humanity?” he questioned.