At the moment, pregnant women in the United Kingdom are offered an ultrasound scan and a blood test to assess the chances that their developing child will have a genetic abnormality. If the test comes back and shows that an abnormality is likely, then diagnostic tests must be performed to confirm the existence of any genetic conditions.
Many women eschew the more invasive diagnostic tests because they carry a risk of miscarriage and must be performed after the first trimester. But all that may change very soon if non-invasive prenatal testing (NIPT) becomes available for all pregnant women through the National Health Service, the U.K.’s nationalized health care system.
I’ve written extensively about NIPT and what it may mean for families in the United States. NIPT involves examining the DNA fragments of the fetus present in the mother’s maternal plasma during pregnancy. This is called cell-free DNA. Once extracted, the DNA is analyzed for abnormalities. NIPT allows for detection of Down syndrome and a host of other chromosomal and genetic conditions.
NIPT is vastly superior to the old way of testing pregnancies. It’s more than 98 percent accurate, carries no risk to the baby and can be performed as early as 10 weeks gestation, earlier than the old tests, which generally started around 12 weeks.
For now, NIPT is not 100 percent diagnostic, which means that if the test comes back positive, a diagnostic test, such as amniocentesis, is still needed to discern with 100 percent certainty whether an abnormality is present.
But NIPT may soon be diagnostic, so all that a pregnant woman will need to know the genetic make-up of her child is a simple first-trimester blood test. In addition the tests may also soon be able to detect risk factors for DNA-based disease that develop over time, such as cancer and Parkinson’s disease.
In the U.K. NIPT is already available in the private sector but it can cost more than $1,000. NIPT is not yet available in the NHS, but it may soon be. The UK National Screening Committee is deciding whether it should be made available through NHS, and a decision is expected within weeks.
Many disability rights advocates and others are concerned that NIPT will lead to a spike in eugenic abortions. Currently in England and Wales, 90 percent of babies diagnosed with Down syndrome are aborted. Of course, not all pregnant women who carry babies with genetic conditions use diagnostic testing. But many more likely will if NIPT becomes the norm.
The growth of NIPT raises a host of questions: How will informed consent be obtained? How will we ensure that genetic counselors remain unbiased when conveying test results? Will the use of NIPT someday by mandatory?
With so many questions surrounding the new test, one thing seems certain: As Mark Bradford, president of the Jerome Lejeune Society, an advocacy group for people with Down syndrome, told me last year, NIPT presages a future that’s “bleak for children prenatally diagnosed with Down syndrome or some other chromosomal abnormalities.”
Daniel Allott is deputy commentary editor for the Washington Examiner
